Ball python temperature?

NO! snakes need a warm and cool side, You need to have a heating element on one side (light, heating pad, ceramic heat emitter etc.) and nothing on the other side as long as the temperature does not get below 80 and the hot spot / basking spot stays around 90. Snakes can not regulate their own body temperature and need to thermoregulate to survive. in the wild they do this by hiding in a cool spot and coming out to bask in the sun. In captivity it is our job to do this for them as reptile keepers. the water would be room temperature and offer no cooling. Please do more research before getting a snake, they are amazing animals but if you don't know what you are doing and get one it will quite literally come back to bite you.

No! Snakes need a variety of temperatures so that they can maintain the preferred body temperature through thermo-regulaton. Balls need a temperature range of 90 F in the basking area, and a background temp 80 F - 85 F. Not only will your electricity bill shoot up (maintaining an entire room at such a high temperature will take a lot of power), but your snake wont be able to thermo-regulate properly in that situation.

Placing the heat pad UNDERNEATH the tank, or placing th heat lamp on top mesh of the enclosure on the OUTSIDE will prevent the risk of burns. Make sure you use a suitable thermostat to prevent over heating.

The water will still be at room temperature of 85. If you want a cooler temperature, put a big shallow pan in the refrigerator and take the door off. That would make the water a little cooler and the snake would have access.