Abstract: This invention discloses a thermal envelope including a pouch (12) and a flap that closes the pouch and thermal capacitance material (18) that lines the pouch, wherein the thermal capacitance material (18) has an initial temperature in a temperature range of −5 degrees C. to 20 degrees C., characterized by the thermal capacitance material having a thermal that maintains a temperature of the medical sample placed in the pouch (12) within the temperature range during a period of time not more than 7 hours from the time the medical sample was placed in the pouch. A method for sending a medical sample from a sampling site to a laboratory is also disclosed.