The basking spot for a Ball Python is inside the warm hide. As long as the heat is there, the air will be warm enough inside the hide. The air directly around the outside of the hot hide may be a little warmer, depending on how big the UTH is. Generally, the air outside the hide is going to be about the same all through the enclosure, which is ok as long as it stays arou 78-80F. If you are using a tank and need to warm the ambient air temp up you can:

1) use a ceramic heat emitter, or a heat bulb.
2) use a space heater to keep the room temperature where you want it.
3) use the house thermostat to keep the whole house at the desired temp.

Since I keep my house at 68F in the winter, I use a space heater in the room I have my snakes in. I have it controlled by a Johnson thermostat set at 81F. It keeps the whole room at that temp so that is what my tubs ambient temp stays around. Inside the warm hides it is about 91F, which is done by the UTH's controlled by my Herpstat thermostat. ...