Low indoor temperatures and morbidity in the elderly.

Low ambient temperatures are particularly harmful to the elderly and in the winter in the UK temperatures in some dwellings may fall to 6 degrees C. The World Health Organization recommends a minimal indoor temperature of 18 degrees C and a 2-3 degrees C warmer minimal temperature for rooms occupied by sedentary elderly, young children and the handicapped. Below 16 degrees C, resistance to respiratory infections may be diminished. Both low and high relative humidities promote respiratory illnesses. At temperatures below 12 degrees C, cold extremities and slight lowering of core temperature can induce short-term increases in blood pressure. Raised blood pressure and increased blood viscosity in moderate cold may be important causal factors in the increased winter morbidity and mortality due to heart attacks and strokes. Deep body temperature does not usually fall until resting clothed elderly people are exposed for two or more hours to an ambient temperature of 9 degrees C or below. Statistics available for the UK population do not support the view that there are large numbers of elderly people suffering from clinical hypothermia, though there may be a larger number in whom hypothermia is undiagnosed when the condition occurs secondary to other disorders.