Q: When you get into bed do you sometimes find that your wife seems strangely cold?
A: Very probably. Female extremities do have a greater tendency to get colder than men's do:
It's because the external temperature at which men's and women's bodies begin conserving heat -- called the set point temperature -- varies by about three degrees.
When surrounding temperatures drop to a certain point, your body will conserve heat by shutting off the blood flow to the hands and feet, making them feel chilled. For women, that temperature is about 70 degrees, while men can hold steady until about 67 or 68 degrees.