The body regular its own internal temperature.  The body reads outside (environment) temperature, adjust by raising or lowering it temperature, and when the temperature constantly change so will the body which put the body into a temperature chaos state. Winter Technique: To help the body when you go to sleep you use the palm  of your hand and place it over the naval (belly button), use a pillow (thin blanket folded up several time) to cover the hand and stomach then use a regular blanket.  Summer Technique: Turn the fan on low if you don't have AC (air condition) to circulate the air.  Just like the winter technique but this time you don't need a regular blanket.  This is how you control temperature chaos.