When sleeping your body temperature normally decreases by a few degrees to help prepare your body for sleep and then decreases a bit more during the sleeping.
Then when you wake up in the morning your body temperature should begin to rise back up to normal.
If your body temperature is increasing at night you could just be too hot or sleeping under too many blankets or your room is just too hot.
You might also have some medical condition that is causing your body temperature to rise during the night so I would speak with a doctor and let them know.
Although it's likely nothing serious but your body may be getting hotter during the night and may be causing you to sweat more.