Is your UTH on a thermostat? (it needs to be)
when a UTH is on a thermostat it isn't on forever, it gets turned on and off (or turned down depending on what type of thermostat you have)
An oven and a UTH are completely different. While the heating elements work on the same principal they are nothing alike. As long as the UTH is on a thermostat you have nothing to worry about. there are literally thousands of them that are running right now and most of them have been running for years.
I can understand an irrational fear but keep in mind a heat lamp/CHE/ any other heat source is just as likely to cause issues.