UTHs on tubs?

Curious if anyone might know anything more along these lines - Running a UTH on a thermostat against the bottom of a rubbermaid tub, would I ever need to worry about the UTH ever potentially melting the plastic? I know that when it's on a thermostat there really isn't a risk since I don't let it go much over 100 degrees to keep the hotspot on the inside of the tank at the right temperature (93 right now), but I've read too many horror stories here and across the internet about thermostats failing and allowing the UTH to go unregulated for periods of time.

This is a total worst-case-scenario, but could letting an unregulated UTH run against the plastic of a tub cause it to melt?

No. I left one on for a day with no thermostat (no snake in tub), and it was fine at 120°.

If people don't use a thermostat or if it fails then it can burn your snake. But it would have to get very hot to melt it and they are not capable of getting that hot. If u have it controlled by something reliable then don't worry. But there are horror stories out there

i have a UTH on my tub which is hooked up to a thermostat and it works perfectly fine.

Thanks guys! I had a feeling my fears were unfounded I just kept having this waking nightmares of going to bed one night, having my thermostat somehow magically fail and waking up to find a giant hole melted in my tub and my snake missing in action - completely silly I know, but I just had to make sure.