<Li> Have shortened extremities </Li> <Li> Have countercurrent blood flow in extremities--this is where the warm arterial blood travelling to the limb passes the cooler venous blood from the limb and heat is exchanged warming the venous blood and cooling the arterial (e.g., Arctic wolf or penguins) </Li> <P> In warm environments, birds and mammals employ the following adaptations and strategies to maximize heat loss: </P> <Ol> <Li> Behavioural adaptations like living in burrows during the day and being nocturnal </Li> <Li> Evaporative cooling by perspiration and panting </Li> <Li> Storing fat reserves in one place (e.g., camel's hump) to avoid its insulating effect </Li> <Li> Elongated, often vascularized extremities to conduct body heat to the air </Li> </Ol>

Describe the chemical reaction that generates heat in the human body