Recommendations:
First of all you should see if you're just feeling hot, or if it can be something serious. Before you go to a doctor, try finding things that can have caused a body overheating (an allergy from food or chemicals for example) so that the doctor has enough information to work on.
You can try increasing the humidity of your room and your body, as well as keeping the room well ventilated by opening the window during the day. Keeping a glass of water on your bedside table can also be useful.
Check the materials that your sheets/covers are made of. Synthetic materials don't transpire properly, and I would recommend a soft wool/cotton material. Also, if your pillow heats up to much, try finding one that doesn't, because having a hot and sweaty head isn't good for you.
You can also try re-designing your room by moving your bed to a cooler place, because as you might know, some walls heat during the day, and release that heat during the night as the go cooling down.
(medical) Conclusion:
You need to be careful, because overheating isn't a nice symptom, and it can lead to other problems. A constant dehydration can also lead to serious problems so keep an eye on that.
(non-medical) Conclusion:
The problem might just be your bed or you sheets, so nothing serious or that you should worry about.
Hope it helped,
BioTeacher101