Thermoregulation in endotherms Endotherms generate most of their heat metabolically. As they are warmer than their environment they tend to lose body heat to their surroundings. • Adaptations for heat conservation include: • Insulation – insulating layers of fat, fur or feathers to prevent heat loss. • Metabolism – metabolic rate can be varied to generate more or less heat. Endotherms also use their skin to vary their rate of heat loss and maintain a constant core body temperature.
Hyperthermia and hypothermia Prolonged exposure to high temperatures can lead to hyperthermia. The body’s core temperature rises above 41°C causing its thermoregulatory mechanisms to break down. When this happens, positive feedback occurs and the person’s body temperature can spiral out of control. A core body temperature of 43°C and higher usually causes death. If the body’s core temperature falls below 35°C a person may suffer from hypothermia. Again the body’s thermoregulatory mechanisms fail and positive feedback occurs leading to a further decrease in temperature.