Welcome to the site!
We need some more information to help you out.
1. What are you using to heat your cage?
2. Do you have anything monitoring the temperatures in the cage?
3. Do you have a thermostat?
4. What type of cage/what size cage are you using?
5. Can you post a picture of the cage and the snake's belly? This thread will show you how to post pictures:
http://ball-pythons.net/forums/showt...with-pictures)
Here are two really good threads that you should check out to make sure that you have everything set up correctly:
Care: http://ball-pythons.net/forums/showt...ius)-Caresheet
Cage Heating: http://ball-pythons.net/forums/showt...t-Thermometers