As far as your snake getting dehydrated: if you provide clean water, the snake will drink if it gets thirsty. Snakes are not like humans, where they need a sip of something with dinner to wash it down.
As to the light and heat mat: I would use the UTH, with the light as back-up heat if the room's ambient air temp is low (cool). If the room feels comfortable to you, it should be fine for the snake. If it's a choice between the two: the snake needs belly heat more than warm air temps.
I have a
50w red light and a UTH. I used the UTH as
the primary heat source. I only use the red light on very cold days, but never @ night
(going thru The Change w/ hot flashes:realhot: & night sweats, so windows stay open year-round. Boyfriend has to wear fleece!:grin01: Luckily, due to Global Warming, this winter has been extremely mild. But I digress...).
When I first got my snake,
I thought I could use both, on timers, all the time.
I experienced a
bad shed (bits & pieces) on her 1st attempt,
so knew the tank was getting too dry. I stopped using the red light and tried misting the aspen daily (which helped some), and 2nd shed was better (a long piece 1inch from ventral, and the remaining shorter piece). :nope: But I knew Nibblet could do better!
I have since made her a moist hide
(using a paper orange juice container & damp shredded paper toweling) which stays in the tank at all times. Since my apartment gets so warm (with building-regulated heating), I turn off the UTH when sun goes down and back on in the morning to simulate winter. Her last two sheds have been perfect.:crazy02: