UTH means under tank heat. an example would be flexwatt, zoo-med reptitherm, etc. you can get them at any petstore, (if you're getting flexwatt you'll need to order it online) and they need to be hooked up to a thermostat to insure they dont get too got a burp the snake.

a gatorade bottle will not work. you won't be able to get the snake out if you need to, it would be too hard to clean, and its clear so it wouldnt provide little to no security.