Abstract: A heater-cooler apparatus of an extracorporeal perfusion system comprises at least one fluid circuit (102, 104) providing a supply of a heat transfer fluid to the perfusion system, a cold storage unit (266), and a refrigeration unit (250) for charging the cold storage unit (266). The cold storage unit (266) comprises a chamber (312) containing a liquid that freezes at a temperature above that to which the heat transfer fluid is cooled by the refrigeration unit (250), and a passage through which the heat transfer fluid is conveyed, the passage extending through the chamber (312). This allows a more effective cold storage unit to be provided.

Abstract: According to some embodiments, a system may treat blood outside the body of a patient. The system may include one or more pumps configured to pump blood in a fluid flow path at a collective rate over 5 liters per minute. The system may include one or more heat exchangers operable to heat at least a portion of the blood to a temperature of at least 42 degrees Celsius and to allow the blood to cool one or more degrees following heating. The system may include one or more convection dialysis modules configured to perform convection dialysis on at least a portion of the blood at least after the one or more heat exchangers allow the blood to cool one or more degrees.

Abstract: Medical devices for inducing hypothermia are disclosed. Induced hypothermia is a treatment used to reduce secondary complications caused by reduced oxygen and blood flow during traumatic injuries and surgeries. However, induced hypothermia also has negative side effects such as shivering and lowered immune system. These devices incorporate Highly-Oriented Pyrolytic Graphite (HOPG) for solid conduction to lower the temperature at targeted locations on and inside the body. The benefits of incorporating HOPG include: highly efficient heat conduction, flexibility in design and manufacture, reduction of dependence on inefficient and unstable fluid-filled implants and catheters, and anti-thrombotic effects.

Abstract: Relatively non-invasive devices and methods for heating or cooling a patient's body are disclosed. Devices and methods for treating ischemic conditions by inducing therapeutic hypothermia are disclosed. Devices and methods for inducing therapeutic hypothermia through esophageal cooling are disclosed. Devices and methods for operative temperature management are disclosed.

Abstract: Closed loop heat exchange catheters having bi-directional flow heat exchange regions and their methods of manufacture and use. The heat exchange region may be formed of expandable or non-expandable tubular conduit(s) that are configured in a series of loops or coiled configuration defining a supply flow path and a return flow path through which heat exchange medium is circulated. The individual loops of convolutions of the coiled configuration may be the same or different size. In some embodiments, the tubular conduit(s) may be passed through generally transverse bore holes formed in a catheter shaft so that the loops or convolutions of protrude from the catheter shaft.

Abstract: A cooling and heating cup holder includes: a pair of holder bodies; a pair of thermoelectric elements having first and second surfaces for heat absorption and heat generation, the first surfaces being installed on the holder bodies; a pair of heat exchange pins provided so as to exchange heat with the second surfaces of the respective thermoelectric elements; a blower disposed at one side of the heat exchange pins and heat-radiating the heat exchange pins; and an extension heat pipe thermally connecting the second surfaces of the respective thermoelectric elements to each other or thermally connecting the respective heat exchange pins to each other.

Abstract: A method for treating acute coronary syndromes (i.e., unstable angina or non-Q-wave MI) or transient ischemic attacks in a human or animal patient by placing a heat exchange apparatus in the patient's vasculature and using that heat exchange apparatus to cool the patient to a temperature (e.g. 30-36 degrees C.) at which platelet inhibition (i.e., inhibition of platelet activation and/or aggregation and/or adhesion) occurs. Anti-shivering drugs or anesthesia may be administered to patients whose body temperature is cooled below that patient's shivering threshold (typically approximately 35.5 degrees C.). If it is determined that platelet inhibition is no longer desirable, such as when the patient is about to undergo a surgical or interventional procedure wherein bleeding could be problematic, the hypothermia-induced platelet inhibition may be rapidly reversed by using the intravascular heat exchange apparatus to re-warm the patient's body to normothermia or near normothermia.

Abstract: Systems and methods for accurate temperature modification of a patient, or selected regions thereof, including inducing hypothermia. The temperature modification is accomplished using an in-dwelling heat exchange catheter within which a fluid heat exchange medium circulates. A heat exchange cassette attached to the circulatory flow lines of the catheter, the heat exchange cassette being sized to engage a cavity within a control unit. A temperature measurement scheme for obtaining body core temperature is provided, including methods of obtaining and analyzing temperature data to provide feedback to the control unit for use in controlling the heating and cooling of the heat exchange medium so as to heat or cool a patient to a desired target temperature.

Abstract: Catheter devices and methods for intravascular heating and/or cooling of human or veterinary patients. The catheter devices generally comprise catheters having inflow and outflow lumens and at least one curvilinear balloon connected to the inflow and outflow lumens such that heat exchange fluid may be circulated through the balloon(s). The catheter is inserted into the vasculature and heated or cooled fluid is circulated through the balloon(s) to heat or cool blood flowing in heat-exchange proximity to the balloon(s), thereby effecting heating or cooling of all or a portion of the patient's body.

Abstract: Devices, systems, and methods are disclosed herein for treatment of a disease, disorder, or condition in a vertebrate subject. A device is provided that includes one or more cooling elements configured to be applied to one or more tissues of a vertebrate subject to modulate at least one activity of brown adipose tissue of the vertebrate subject, wherein at least a portion of the one or more cooling elements is configured to be implantable, and a programmable controller configured to provide instructions to the one or more cooling elements in response to information regarding one or more physiological conditions of the vertebrate subject.

Abstract: Closed loop heat exchange catheter systems and methods for preparing and using such systems wherein a reservoir or fluid bag is connected to the catheter system and used for at least priming of the system with a heat exchange fluid.

Abstract: A heat exchange fluid supply system for supplying a heat exchange fluid to an intravascular heat exchange catheter includes a disposable cassette having a bulkhead and an external heat exchanger, and which is configured to operate in combination with a reusable master control unit. The bulkhead includes a reservoir section and a pump section. The reservoir section is provided with a means to monitor the amount of heat exchange fluid that is in the system. The bulkhead provides the mechanism for priming the system with heat exchange fluid from an external source and for circulating fluid to the catheter in a closed circuit. The pump section is configured to allow for pumping of heat exchange fluid at a constant pressure.

Abstract: A catheter is adapted to exchange heat with a body fluid, such as blood, flowing in a body conduit, such as a blood vessel. The catheter includes a shaft with a heat exchange region disposed at its distal end. This region may include hollow fibers which are adapted to receive a remotely cooled heat exchange fluid preferably flowing in a direction counter to that of the body fluid. The hollow fibers enhance the surface area of contact, as well as the mixing of both the heat exchange fluid and the body fluid. The catheter can be positioned to produce hypothermia in a selective area of the body or alternatively positioned to systemically cool the entire body system.

Abstract: The present invention provides a method and apparatus for controlling the internal body temperature of a patient. According to the present invention, a catheter is inserted through an incision into a large blood vessel of a patient. By selectively heating or cooling a portion of the catheter lying within the blood vessel, heat may be transferred to or from blood flowing within the vessel and the patient's body temperature may thereby be increased or decreased as desired. The invention will find use in treating undesirable conditions of hypothermia and hyperthermia, or for inducing a condition of artificial hypothermia when desired.

Abstract: The present invention provides a method and apparatus for controlling the internal body temperature of a patient. According to the present invention, a catheter is inserted through an incision into a large blood vessel of a patient. By selectively heating or cooling a portion of the catheter lying within the blood vessel, heat may be transferred to or from blood flowing within the vessel and the patient's body temperature may thereby be increased or decreased as desired. The invention will find use in treating undesirable conditions of hypothermia and hyperthermia, or for inducing a condition of artificial hypothermia when desired. The method and system further provide for the cooling of initially hypothermic patients whose blood or body temperature has been warmed above the desired target level and the warming of initially hyperthermic patients whose blood or body temperature has been cooled below the desired target temperature.

Abstract: A system and method for adding or removing heat from a heat exchange fluid circulating between an external heat exchanger and an intravascular heat exchange catheter is described. The system includes a two stage cooling system providing for a high rate of cooling in one stage and a lower rate of cooling in a second stage. Both stages may be used to provide maximal cooling while the second stage is used to provide improved control of the cooling rate as a target temperature is approached. The second stage may also be used to provide heat to the heat exchange fluid.

Abstract: The present invention relates to a portable apparatus for warming biocompatible fluids for use in the treatment of injured patients and a method of heating a biocompatible fluid to treat a patient experiencing hypothermia. The present invention may be used to warm intravenous fluids for trauma resuscitation or to warm air from a ventilator circuit. The portable nature of the present invention makes it highly suitable for field applications, such as a forward surgical hospital near a combat zone.

Abstract: Apparatus, systems and methods for cooling or warming the temperature of all or a portion of the body of a human or animal subject to treat disorders including but not limited to sepsis, septic shock or other inflammatory or infectious conditions which can result in shock, hypoxia, ischemia and/or multiple organ failure in human or animal subjects.

Abstract: Methods and apparatus for the prevention and treatment of shivering encountered during therapeutic temperature regulation are disclosed that utilize an active system of counterwarming such that the timing and intensity of warmth provided to selected body areas is regulated dynamically in response to such factors as the extent of cooling applied to the core, the degree of shivering encountered, and patient temperature. Additionally, methods and apparatus are disclosed for the measurement and quantification of shivering for use in this and other applications.

Abstract: Methods and apparatus for preventing myocardial infarction, or lessening the size/severity of an evolving myocardial infarction, by cooling at least the affected area of the myocardium using an intravascular heat exchange catheter. The heat exchange catheter may be inserted into the vasculature (e.g., a vein) and advanced to a position wherein a heat exchanger on the catheter is located in or near the heart (e.g., within the vena cava near the patient's heart). Thereafter, the heat exchange catheter is used to cool the myocardium (or the entire body of the patient) to a temperature that effectively lessens the metabolic rate and/or oxygen consumption of the ischemic myocardial cells or otherwise protects the ischemic myocardium from undergoing irreversible damage or infarction.

Abstract: A catheter has a hollow conduit through which working fluid from a heat exchange system flows. The conduit in turn is configured to extend along a longitudinal central axis in a continuously varying non-constant azimuthal orientation so that it defines a non-round enclosed passageway through which blood can flow to exchange heat through a wall of the conduit with the working fluid flowing within the conduit.

Abstract: An intravascular heat exchange catheter has serpentine-like supply and return conduits circulating working fluid with a heat exchange system to warm or cool a patient in which the catheter is intubated.

Abstract: The present invention discloses a heat exchanging assembly with a body adaptable to a catheter for measuring blood flow rate with a supply system for providing the heat exchanging medium to the heat exchanging assembly at a constant temperature and constant flow rate. The heat exchanging assembly comprises a heat exchanging element, a plurality of temperature sensors, a sensor lumen and an inflation lumen.

Abstract: Methods and systems for infusing a cooled infusate to a target location in a patient are described. A temperature of the blood and infusate admixture upstream of the catheter as well as at other locations along the catheter may be monitored and a feedback system utilized to control the volume, temperature, and/or infusion rate of the infusate so as to achieve a predetermined temperature at the target location. Control may also be based on the patient's native vessel flow rate. The system may monitor or calculate hematocrit upstream of the catheter and adjust infusion so as to provide sufficient oxygenation of the blood and infusate admixture. The system may also monitor reflux of the infusate past a distal end of the catheter and reduce infusion upon the detection of reflux.

Abstract: A method for treating acute coronary syndromes (i.e., unstable angina or non-Q-wave MI) or transient ischemic attacks in a human or animal patient by placing a heat exchange apparatus in the patient's vasculature and using that heat exchange apparatus to cool the patient to a temperature (e.g. 30-36 degrees C.) at which platelet inhibition (i.e., inhibition of platelet activation and/or aggregation and/or adhesion) occurs. Anti-shivering drugs or anesthesia may be administered to patients whose body temperature is cooled below that patient's shivering threshold (typically approximately 35.5 degrees C.). If it is determined that platelet inhibition is no longer desirable, such as when the patient is about to undergo a surgical or interventional procedure wherein bleeding could be problematic, the hypothermia-induced platelet inhibition may be rapidly reversed by using the intravascular heat exchange apparatus to re-warm the patient's body to normothermia or near normothermia.

Abstract: A catheter is adapted to exchange heat with a body fluid, such as blood, flowing in a body conduit, such as a blood vessel. The catheter includes a shaft with a heat exchange region disposed at its distal end. This region may include hollow fibers which are adapted to receive a remotely cooled heat exchange fluid preferably flowing in a direction counter to that of the body fluid. The hollow fibers enhance the surface area of contact, as well as the mixing of both the heat exchange fluid and the body fluid. The catheter can be positioned to produce hypothermia in a selective area of the body or alternatively positioned to systemically cool the entire body system.

Abstract: The invention relates to a device for conveying heated air to a person and comprises an air-permeable inner sheet and an air-impermeable outer sheet which are connected to one another by welds in order to form a panel-like shape in the inflated state. The welds produce a main duct having, viewed at the inlet end and in the non-inflated state, a main duct width. The main duct is delimited by at least one first series of elongate first welded strips, the first intermediate spaces which are in line with one another. The length of each of these first intermediate spaces, viewed in the non-inflated state, is in each case smaller than the main duct width. The length of each first welded strip is at least 15% of the main duct width and at most 80% of the main duct width.

Abstract: The present invention advantageously provides a method and system for cryogenically ablating large areas of tissue within the left atrium. In an exemplary embodiment a cryotherapy device includes a catheter body having a substantially fixed diameter, a proximal end and a distal end; a first lumen for permitting passage of a cooling fluid from the proximal end to the distal end; a second lumen permitting return of the cooling fluid from the distal end to the proximal end; and an ablation element expandable from a first diameter that is substantially the same as the diameter of the catheter body to a second diameter that is at least twice the diameter of the catheter body, the ablation element having a surface portion that conforms to the uneven surface topography of the cardiac tissue. The ablation element can include one or more balloon and/or a flexible element that is deformed by moving the distal end of the catheter toward the proximal end of the catheter.

Abstract: A compact heat exchanger for veno-venous perfusion-induced hyperthermia includes an integral pneumatic pump and a hollow tubule heat exchange array. A veno-venous perfusion-induced hyperthermia system incorporating the compact heat exchanger is described. The heat exchanger provides a compact, efficient design allowing a lesser heat exchanging surface area and lesser required pumping power compared to conventional systems. In turn, the system provides a shorter blood circuit compared to conventional systems, allowing maintaining a lower blood temperature than such conventional systems while supplying sufficiently heated blood to patient visceral organs to provide a therapeutic effect, such as in supplementing chemotherapy drugs.

Abstract: Apparatus, systems and methods for cooling or warming the temperature of all or a portion of the body of a human or animal subject to treat disorders including but not limited to sepsis, septic shock or other inflammatory or infectious conditions which can result in shock, hypoxia, ischemia and/or multiple organ failure in human or animal subjects.

Abstract: A catheter is adapted to exchange heat with a body fluid, such as blood, flowing in a body conduit, such as a blood vessel. The catheter includes a shaft with a heat exchange region disposed at its distal end. This region may include hollow fibers which are adapted to receive a remotely cooled heat exchange fluid preferably flowing in a direction counter to that of the body fluid. The hollow fibers enhance the surface area of contact, as well as the mixing of both the heat exchange fluid and the body fluid. The catheter can be positioned to produce hypothermia in a selective area of the body or alternatively positioned to systemically cool the entire body system.

Abstract: Systems and methods for accurate temperature modification of a patient, or selected regions thereof, including inducing hypothermia. The temperature modification is accomplished using an in-dwelling heat exchange catheter within which a fluid heat exchange medium circulates. A heat exchange cassette attached to the circulatory flow lines of the catheter, the heat exchange cassette being sized to engage a cavity within a control unit. A temperature measurement scheme for obtaining body core temperature is provided, including methods of obtaining and analyzing temperature data to provide feedback to the control unit for use in controlling the heating and cooling of the heat exchange medium so as to heat or cool a patient to a desired target temperature.

Abstract: Devices, systems and methods for treating disorders characterized by low cardiac output. The devices, systems and methods use intra-aortic balloon counterpulsation in combination with hypothermia of all or a portion of a human or veterinary patient's body to improve coronary perfusion and cardiac output. To effect the hypothermia, a heat exchange catheter may be positioned in the a patient's vasculature separately from the intra-aortic balloon counterpulsation catheter. Alternatively, a combination Intra-aortic balloon counterpulsation/heat exchange catheter may be utilized. Such combination catheter comprises a) a catheter sized for insertion into the aorta, b) a counterpulsation balloon and c) a heat exchanger. A drive/control system receives temperature and electrocardiograph signals and drives the inflation/deflation of the counterpulsation balloon as well as the heating/cooling of the heat exchanger.

Abstract: Methods and apparatuses for temperature modification of a patient, or selected regions thereof, including an induced state of hypothermia. The temperature modification is accomplished using an in-dwelling heat exchange catheter within which a fluid heat exchange medium circulates. A heat exchange cassette of any one of several disclosed variations is attached to the circulatory conduits of the catheter, the heat exchange cassette being sized to engage a cavity within one of various described re-usable control units. The control units include a heater/cooler device, a user input device, and a processor connected to receive input from various sensors around the body and the system. The heater/cooler device may be thermoelectric to enable both heating and 15? cooling based on polarity. A temperature control scheme for ramping the body temperature up or down without overshoot is provided.

Abstract: Catheter devices and methods for intravascular heating and/or cooling of human or veterinary patients. The catheter devices generally comprise catheters having inflow and outflow lumens and at least one curvilinear balloon connected to the inflow and outflow lumens such that heat exchange fluid may be circulated through the balloon(s). The catheter is inserted into the vasculature and heated or cooled fluid is circulated through the balloon(s) to heat or cool blood flowing in heat-exchange proximity to the balloon(s), thereby effecting heating or cooling of all or a portion of the patient's body.

Abstract: A patient temperature control catheter (10) includes working fluid supply (16) and return (18) lumens through which working fluid circulates to exchange heat with a patient in whom the catheter is positioned. At least one lumen is defined by plural coils (32) axially spaced from each other. At least a first coil is a large coil that inflates with working fluid to seat against a wall of a blood vessel in which the catheter is positioned, with blood flowing through the coil so as not to block blood flow in the vessel. Alternate centering structures (116) are disclosed.

Abstract: A transatrial intravascular temperature management catheter has a lower heat exchange segment positionable in the inferior vena cava and an upper heat exchange segment positionable in the superior vane cava, with a connecting segment lying between the two and positionable in the right atrium. A temperature sensor on the distal tip of the upper heat exchange segment provides accurate core body temperature signals for feedback purposes since the blood flowing past the sensor has not yet reached the heat exchange segment.

Abstract: A catheter is adapted to exchange heat with a body fluid, such as blood, flowing in a body conduit, such as a blood vessel. The catheter includes a shaft with a heat exchange region disposed at its distal end. This region may include hollow fibers which are adapted to receive a remotely cooled heat exchange fluid preferably flowing in a direction counter to that of the body fluid. The hollow fibers enhance the surface area of contact, as well as the mixing of both the heat exchange fluid and the body fluid. The catheter can be positioned to produce hypothermia in a selective area of the body or alternatively positioned to systemically cool the entire body system.

Abstract: Methods for cerebral and systemic cooling via a patient's nasopharyngeal cavity are described. In one method, a cooling assembly is inserted into a nasal cavity through a patient's nostril. A substantially dry gas is delivered through a lumen of the catheter onto the surface of the patient's nasal cavity. Evaporative heat loss cools the patient's nasal cavity. If additional cooling is needed, a liquid coolant is delivered through a separated lumen of the catheter. The liquid coolant is nebulized at a plurality of delivery ports on the distal end of the catheter and is delivered onto the surface of the patient's nasal cavity in combination with the dry gas. The dry gas enhances evaporation of the nebulized coolant and additional cooling is provided from the evaporative heat loss of the liquid coolant.

Abstract: A kit of parts comprises a system and instructions for use for controlling patient temperature which uses a central venous line catheter having a heat exchange element. The central venous line catheter is provided with one or more lumens for providing access to the central blood supply of the patient, and with additional lumens for communicating heat exchange fluid to the heat exchange element. Heat exchange fluid temperature is controlled through a feed back loop in which patient temperature is sensed and used to control a temperature control unit comprising a heating device and/or a cooling device in heat exchange relationship with the heat exchange fluid. A tubing set transports the heat exchange fluid between the central venous line and the temperature control unit, with a pump serving to circulate the fluid in a closed fluid circuit in the system.

Abstract: A catheter apparatus configured to provide a delivery system for standard intervention devices typically used during emergency angioplasty and to provide rapid localized cooling to organs at risk of ischemic and reperfusion injury. The catheter apparatus including a catheter shaft having an inner core defining at least two coolant flow lumens adjacent to a blood conveyance lumen. Each coolant flow lumen in thermal contact with the blood conveyance lumen and thermally insulated from each other and the exterior surfaces of the catheter shaft.

Abstract: Embodiments of the invention provide a system for temperature control of the human body. The system includes an indwelling catheter with a tip-mounted heat transfer element. The catheter is fluidically coupled to a console that provides a heated or cooled heat transfer working fluid to exchange heat with the heat transfer element, thereby heating or cooling blood. The heated or cooled blood then heats or cools the patient's body or a selected portion thereof. In particular, strategies for optimizing the rewarming of patients for various medical procedures are provided, including stroke, neurosurgery, and myocardial infarction.

Abstract: Closed loop heat exchange catheter systems and methods for preparing and using such systems wherein a reservoir or fluid bag is connected to the catheter system and used for at least priming of the system with a heat exchange fluid.

Abstract: A connector assembly for catheters having closed loop flow circuits, such as some balloon catheters and heat exchange catheters. The connector assembly comprises first and second connector bodies that may be connected and disconnected from one another. When the connector bodies are disconnected, a syringe or negative pressure source may be attached to withdraw residual fluid from the catheter's closed loop circuit and to deflate any expandable portion of the closed loop circuit (e.g., balloon or expandable heat exchanger). A one way flow valve prevents make up air or other fluid from entering the catheter while the negative pressure is being applied. Also disclosed are sterility barrier assemblies for all types of catheters.

Abstract: A capillary tube bundle sub-assembly for use in an extracorporeal heat exchanger includes a continuous capillary tubing wound about a core to define a plurality of capillary layers each including a plurality of capillary segments. The capillary segments each define opposing terminal ends adjacent opposing ends of the core. The capillary segments of each layer are circumferentially aligned relative to an axis of the core, with each successive layer being radially outward of an immediately preceding layer. The capillary segments are non-parallel with the axis, spiraling partially about the axis in extension between the opposing terminal ends. Each capillary segment forms less than one complete revolution (i.e., winds less than 360°). The segments within each layer are substantially parallel with one another; however, an orientation of the segments differs from layer-to-layer such as by pitch or angle.

Abstract: A catheter is adapted to exchange heat with a body fluid, such as blood, flowing in a body conduit, such as a blood vessel. The catheter includes a shaft with a heat exchange region disposed at its distal end. This region may include hollow fibers which are adapted to receive a remotely cooled heat exchange fluid preferably flowing in a direction counter to that of the body fluid. The hollow fibers enhance the surface area of contact, as well as the mixing of both the heat exchange fluid and the body fluid. The catheter can be positioned to produce hypothermia in a selective area of the body or alternatively positioned to systemically cool the entire body system.

Abstract: A catheter is adapted to exchange heat with a body fluid, such as blood, flowing in a body conduit, such as a blood vessel. The catheter includes a shaft with a heat exchange region disposed at its distal end. This region may include hollow fibers which are adapted to receive a remotely cooled heat exchange fluid preferably flowing in a direction counter to that of the body fluid. The hollow fibers enhance the surface area of contact, as well as the mixing of both the heat exchange fluid and the body fluid. The catheter can be positioned to produce hypothermia in a selective area of the body or alternatively positioned to systemically cool the entire body system.

Abstract: An intravascular heat transfer device is provided with a mixing-inducing surface formed by an easily manufacturable process. The device can have a plurality of elongated, articulated segments, each having a mixing-inducing exterior surface. A flexible joint connects adjacent elongated, articulated segments. The device may be conveniently formed, e.g., by vapor deposition or molding, and further lacks undercuts so that the same may be conveniently removed from, e.g., a two-part mold.

Abstract: A catheter is adapted to exchange heat with a body fluid, such as blood, flowing in a body conduit, such as a blood vessel. The catheter includes a shaft with a heat exchange region disposed at its distal end. This region may include hollow fibers which are adapted to receive a remotely cooled heat exchange fluid preferably flowing in a direction counter to that of the body fluid. The hollow fibers enhance the surface area of contact, as well as the mixing of both the heat exchange fluid and the body fluid. The catheter can be positioned to produce hypothermia in a selective area of the body or alternatively positioned to systemically cool the entire body system.

Abstract: A catheter is adapted to exchange heat with a body fluid, such as blood, flowing in a body conduit, such as a blood vessel. The catheter includes a shaft with a heat exchange region disposed at its distal end. This region may include hollow fibers which are adapted to receive a remotely cooled heat exchange fluid preferably flowing in a direction counter to that of the body fluid. The hollow fibers enhance the surface area of contact, as well as the mixing of both the heat exchange fluid and the body fluid. The catheter can be positioned to produce hypothermia in a selective area of the body or alternatively positioned to systemically cool the entire body system.