Eli5: why does our body temperature drop when we sleep?
In: 6
Energy preservation. No need to have muscles hot and ready when you’re unconscious. From memory, if you’re circadian rhythm in correctly attuned to your natural environment, your blood pressure (and temperature) should ramp up sharply about an hour before you wake up, or on first light.
Your body is going into a state of rest, where fewer metabolic processes (digestion, active movement, etc) are going on, which means less heat is being created.