Why constantly soak in cold water when there's heat.

[Will0W783]

I don't agree with using undertank heaters for snakes. Snakes are baskers in the wild...they are evolved to handle overhead sunlight and the resulting heat from that. Does that mean the ground- rocks, dirt, etc- doesn't get hot in their natural climate? No, but excessive belly heat in captivity has been known to lead to constipation, burns, and digestive maladies (What's Wrong with My Snake? by Dr. John Rossi, DVM). It sounds to me like you don't have a good ambient temperature or an adequate gradient, if your described temperatures are indeed correct. I would turn off your heating pad (101 surface temp is a bit hot and may actually be uncomfortable for the snake to crawl across) and rely on your heating lamps only. When we speak of heat gradient, we are speaking of air temperatures, not the surface temperature of a light. Ambient heat would be the steady baseline temperature of the cage not under the light. You want a basking area (6inches-12inches) underneath the light of about 88-90. I would say that the 75 degree cool end is a bit too cold, but the 140 degree basking area is way too hot. Also are you using a digital temp gun to measure your temperatures?

My suggestions to you are to:
1. turn off the heating pad to eliminate belly heat
2. use a substrate that holds in warmth (aspen or cypress mulch are good for this)
3. Recheck your temperatures after 24 hours
4. If you still have such an extreme gradient- you might want to use a smaller wattage bulb and then use one at the hot end and one slightly more to the middle of the cage, to set up a more steady gradient. In my opinion, your hot end is way too hot and your cool end is too cold.
5. Check for mites in the water- remove the snake and pour the water out in increments into a white sink with the drain plugged.

6. Make sure your snake has other hiding places. An insecure snake will often just hang out in the water dish if no hides are provided, as the dish provides a tight spot to wedge into and feel slightly more secure.

Also, keep in mind that Burmese pythons like water. In the wild, they hang out near lakes and swamps. I tend to give my Burm a bathtub soak at least once a week- and he loves it. I let him in the bathroom and start filling up the tub and he will just slither right on into it.