Body Temperature

The body generates heat as a result of chemical reactions taking place in it.

Energy is constantly lost from the surface of the body through the skin as heat. A small amount of heat is also lost with expired air, urine and faeces.

The rate at which heat (energy) is lost from the body depends on conditions such as the temperature of the surroundings, how much skin is exposed and the level of activity of the body.
Normally, body temperature is regulated by homeostatic mechanisms and maintained at a more or less constant value. Variation from this value may indicate a failure of these mechanisms and a probable health problem. However, the body can produce a physiological response to conditions such as fever and will raise the body temperature to aid recovery.
 

You should be able to explain the significance of the temperature range that a healthy body can withstand and body temperatures that are dangerously high or low.

The range of body temperatures measured in the mouth:
normal                                                                  - 36.8°C ; range 36.5 to 37.2°C
death                                                                    - below 25°C
hypothermia                                                         - 32°C
fever                                                                      - above 37.2°C
heat exhaustion or heat stroke                           - likely if above 38°C in absence of infection
high temperatures that would lead to death      - above 43°C

how temperature is controlled and regulated by the nervous system, the circulatory system and the skin. You should be able to describe the temperature control mechanisms of sweating, vasodilation, vasoconstriction and shivering;

• the circumstances in which particular individuals may be at risk of hypothermia, heat exhaustion or heat stroke.