And some people who use aluminum tape, have reported never having problems....so honestly it's somewhat a matter of opinion. Just be sure its secure, and you'll be fine....you don't want the probe coming off, and causing a heat spike, killing your snake.

On a sidenote, A neat trick I learned on here, is actually plugging the thermometer into a dimmer, and adjusting it, so in case the probe becomes detached, it won't cause such a heat spike.