You may have noticed you’re not the only woman who steals her boyfriend’s sweaters.
Your male coworkers are perfectly comfortable while you’re shivering next to a space heater. Or maybe your coed friends want to sit on the patio of a restaurant while you’re gaze wistfully at the warm, cozy interior. Your female friends can relate, but when you’re with the guys, you feel like you can never get warm.
As it turns out, you’re right. It’s not just you. Research reveals several reasons why you feel like you need to wear two layers more than your male friends –– and it’s not just for the fashion.
Lower metabolic rate
Researchers from the Baltimore Veterans Affairs Medical Center studied 328 healthy men and 194 women ages 17-81 years old to determine an average metabolic rate. In their study, which was published in the Journal of Applied Physiology, the researchers found their results “support a lower [resting metabolic rate] in women than in men that is independent of differences in body composition and aerobic fitness.”
When your metabolism burns food in your body, heat is a byproduct. So with more metabolic work, men tend to be warmer at rest than women.
Constricted blood vessels
Jacqueline M. Koski, a doctor of osteopathic medicine for Aurora Health Care, says women’s blood vessels don’t efficiently warm the skin because they tend to be located farther from the surface of the skin than men’s blood vessels. When they are farther from the skin surface, they don’t warm the skin as efficiently.
Women also tend to have more constricted blood vessels. That results in less warm blood reaching the skin surface.
Less (or no) body hair
CBHS Health Fund, a not-for-profit based in Australia, details how men have more body hair than women due to a combination of genetics and social practices that encourage women to shave it. Body hair provides natural warmth, so when your legs and arms are smooth, you may feel colder.
Dr. Koski says that throughout the menstrual cycle, a woman’s basal temperature (the resting body temperature) changes. When it’s lower, you’ll feel colder. Later in life, perimenopausal (aka “premenopausal”) and menopausal women may also have hot flashes that are sometimes followed by chills as the body struggles to regulate its body temperature.
Unfortunately, if our biology is any indication, it looks like we’ll always be fighting our male roommates and coworkers for power over the thermostat. Still, if you live with more men than women, at least you won’t need to share the blanket on the couch as much.