Abstract: In the field of obtaining cardiovascular information from the mammal body (2) in a measurement action performed during a measurement period including a period following a moment at which a local spot of a temperature that significantly deviates from the temperature of the mammal body (2) has been created in the blood vascular system of the mammal body (2), values representing temperature difference to a baseline temperature are measured at at least one position close to, on or in the mammal body (2) throughout the measurement period by means of a measurement device (20) including at least one ultra-sensitive sensor (21) with a high resolution that is configured to enable recordation of at least two subsequent indicator dilution curves in a temperature difference course relating to a respective side of the heart. A practical example of the sensor (21) is a photonic sensor such as a Fiber Bragg Grating sensor.