Chilly

I'm sitting here in front of my computer, shivering. I'm wearing two layers of clothing and contemplating adding a third. The problem is the thermostat. I switched it from heating to air conditioning a couple of weeks ago, and I promised myself that would be the last time.

Every spring and fall I go through this -- air conditioner on the warm days, heater on the cold days (and nights). Isn't there some thermostat I can buy that I can just set to a temperature and it'll know whether the heater or air conditioner should kick in?