Endotherms, such as cougars, have a high metabolic rate which allows them to generate heat internally. This is achieved by burning food to produce energy, and this heat is then distributed throughout the body. Endothermy also allows animals to maintain a higher body temperature than their surroundings, which is necessary for many biological processes.
Cougars are well-adapted to their environment and are able to maintain their body temperature even in cold climates. Their thick fur and high metabolic rate help them to stay warm, and they also have the ability to conserve heat by reducing their activity levels when necessary.