Research shows that while both men and women’s core temperatures fluctuated throughout the day, Women are naturally colder than men and here are a few scientific reasons why women always take their boyfriend’s sweater.

1. There’s a difference in extremities.

You might often see women rubbing their hands together to warm up. That’s because, on average, women’s hands and feet tend to be three degrees colder than men’s. The reason this happens is because women are actually better at conserving heat than men. Their bodies pull the heat back to their organs to conserve warmth when it is cold.

2. Men have higher metabolism.

Men’s metabolisms, on average, run 23 percent higher than women’s. The speed of your metabolism is how quickly your body burns food to give you the fuel it needs. This process causes the body to heat up. Since men’s metabolisms run at a higher rate, their bodies are warmer because they are burning more calories. Women’s metabolisms run slower, therefore burning calories at a slower speed and not warming their bodies up as much. Try these easy tips to jump start your metabolism.

3. Men have more muscle.

Biologically, women have more fat and men have more muscle. Both fat and muscle generate heat, but in different ways. Fat conserves heat and traps it in the core, but only below the skin. This means that when your skin cools down, you feel the cold even if your core may still be warm.

4. Menstruation is a factor.

Women’s body temperatures tend to fluctuate throughout menstruation because of the change in hormone levels. The temperature change is even more drastic for women who are on hormonal birth control. Therefore, depending on where they are in their cycle, women could be more sensitive to cold temperatures than normal.