Hypothermia results from general body cooling and may occur rapidly in water or more slowly in air (death occurs due to heart failure). Elderly people are particularly susceptible to the latter condition, partly because those most susceptible are least sensitive to the cold, and partly because there is a drop in deep body temperature with age. Open-air work during the winter season causes inadequately protected hands to lose dexterity. Drivers with numb hands, and others working with machinery, electricity and tools, are susceptible to accidents as a result of lost manipulative ability
Although no definite information is available, it is thought that the incidence of hypothermia as a major contributory factor to death is much higher than indicated by available statistics, because hypothermia is less evident than the final cause, such as heart failure.