The old and the cold

The political debate in Britain over the withdrawal of universal winter fuel payments to pensioners reminded us of research conducted in the 1980s on thermoregulation, the factors which affect it, and the consequences of any impairments in the mechanisms involved. Admission rates of older adult patients with fractured femur rose as ambient temperature fell, with that of severely malnourished patients rising by 300 % and of normally nourished ones by only 30 %. The severely malnourished had a reduction in core temperature of ≥1 °C, whereas the well-nourished maintained normothermia. The studies also suggested that there was a causal link between undernutrition, mild hypothermia and accidents which might be due to more than just a lack of insulating fat. Whereas the well-nourished had a normal response to a cooling stimulus, i.e. a 10 % increase in metabolic rate, sufficient to maintain core temperature, this response was lost in the malnourished group. Annually, there are about 9 cold deaths for every 1 heat death. Similar thermoregulatory problems have faced polar explorers as they suffer hypothermia and physical incapacity due to malnutrition consequent on high energy expenditure and negative energy balance. The physiology of thermoregulation, its relationship to nutritional state and the consequences of any impairment in function are the same in older adults and fit polar explorers. Hence, there are sound medical as well as humanitarian reasons for ensuring that older adults are kept warm and well fed in winter.