The battle of the sexes, the battle of the thermostat
At this time of year, sunshine is a distant memory and most of us spend our evenings huddled indoors with the central heating on. So why is it that women spend their time shivering under layers of jumpers and trying to turn the thermostat up, while their men are in T-shirts?
The answer probably lies in evolution. It's hard not to realise that men and women are different, and many of those differences arise from survival of the fittest. Homosapiens evolved in the tropics, and dying from too much heat was much more of a risk than succumbing to hypothermia. In those days, men were out getting hot and sticky hunting and gathering and women stayed at home looking after the children. That meant men needed highly evolved ways of avoiding overheating, which is where sweating comes in (remember the old adage about horses sweating, men perspiring and women glowing?). Men really do sweat more than women - but next time you're washing his sweaty socks, you can blame it on evolution.
Men were doing more exercise, which helped keep them warm. Women were also smaller, meaning they had a higher surface area to volume ratio - and the surface of your body is where you lose heat from. Women, therefore, were more prone to dying from hypothermia and evolved with several differences:
- They have a more even distribution of fat around the body. This protects the vital internal organs from getting cold, but also insulates the skin from the body's heat. This means a woman's skin tends to be colder in cold weather than a man's - and since most of the body's cold sensors are in the skin, women get more messages to the brain telling them they're cold.
- While men regulate their body temperature largely through sweating, women tend to shut down the circulation to their hands and feet to preserve the heat deep inside their bodies - their core. Interestingly, women's core temperature is slightly higher than men's - a real life example of 'cold hands, warm heart'. It may also explain why women are much more prone than men to Raynaud's.
- Finally, let's talk premenstrual syndrome. When women are premenstrual, their core body temperature is higher but their temperature regulation mechanisms don't work in the same way - they seem to be less efficient. They feel the cold more and they feel pain more (1) - you have been warned …