For starters, women’s bodies produce less heat than men’s. Men generally expend more calories than women, about 23 percent more in fact. Spent calories are essentially burnt fuel. The body is a furnace, and a male body runs far hotter. Most of this variance is explained by the fact that men contain much more heat-generating muscle, but even if body composition and activity are accounted for, women’s bodies still run 3 to 10 percent cooler. A good chunk of the energy we expend gets dissipated as heat, and this heat warms our skin, clothes, and immediate surroundings. As walking, talking space heaters, men are much more powerful.

Of course, being cold is not necessarily the same as feeling cold. But in this arena, women are also prone to feeling frigid. Owing perhaps to their more limited distribution of muscle, women’s extremities run much cooler than men’s. A 1998 study found that women’s average hand temperature hovers around 87.2 °F, while men’s averages 90 °F

“Women may be built to keep their vital organs nice and toasty, but their chilly fingers and toes could explain why they perceive themselves as cold more readily than men,” io9’s Robbie Gonzalez proffered.