New evidence shows that being cold is responsible for more preventable (excess) deaths than the flu in winter.
Researchers from Queen Mary and Westfield College, London, recorded the number of deaths due to all causes and flu from 1970 to 1999 in southeast England. They found that death rates went up as the temperature went down from 18 degrees C.
There are around 50,000 preventable deaths every year in the UK during winter, and only 2.4 per cent of these are related to the flu.
The researchers noted that with a moderate wind, even at temperatures as high as 5 degrees C, a person's blood undergoes major changes in composition in as little as 20-30 minutes. The blood thickens and becomes stickier, increasing the chances of heart attack, clot formation and respiratory infection.
Also, unlike places which are consistently cold, such as Siberia (which has no excess winter deaths), people who live in countries with fluctuating seasonal temperatures are often poorly prepared for cold weather.
The authors recommend that physicians advise their older, more vulnerable patients to bundle up well before going out into the cold, avoid prolonged exposure and seek protection from the wind (BMJ, 2002; 324: 89-90).