The study found that women had a cooler lower critical temperature – resembling an “arctic” shift compared to men.
Lead study author Robert Brychta, of the National Institute of Diabetes and Digestive and Kidney Diseases, told The New York Post: “Skin temperatures really didn’t vary that differently than the men.
“What we did find was that the women tended to have a lower resting metabolic rate than the men, and that’s related to their smaller body sizes.
“The smaller person, whether it’s a man or a woman, is going to produce a lower amount of heat.”
Men’s resting metabolic rate is on average around 23% higher than women due to a greater lean muscle mass which burns more calories at rest than fat tissue.
More muscle mass generates more body heat.
Brychta did note a possible exception to this principle however.
“The women tended to have a higher level of insulation from their higher body fat percentage as a group.”
Women’s heat production scaled with body size, and resistance to heat loss was related to body fat, according to the research.
Brychta explained: “If you have a smaller woman compared to a larger man, they’re definitely going to feel colder.
“A smaller man that’s very thin and has a lower body fat percentage, then they also would feel colder than a bigger person.”
The study concluded that the main contributors to individual differences in thermoregulation are body size, type and composition, which may be partly mediated by sex.
Previous studies had suggested that women may be colder because they have naturally higher core temperatures, making cold air feel even cooler to the body.
External factors, such as stress levels, cigarette use, diet and hormonal birth control, also play a role in affecting our body temperatures.
