The generation of heat by the human body has been likened to that of a furn
ace. In response to winter conditions or prolonged immersion in cold water,
heat may be lost from the body more quickly than it is produced leading to
hypothermia. Various factors, environmental and individual, predispose a p
erson to hypothermia when walking on dry land or during cold water immersio
n. Retention of the insulating properties of the clothing worn is of crucia
l importance in protecting against cold injury both on land and in water. A
nthropometric characteristics and behavioural and physiological responses a
lso influence the probability of survival under these conditions. Practical
recommendations for behaviour that will enhance survival during prolonged
exposure to cold on land or to immersion in cold water are considered.