Make sure it is not touching anything flammable.
CHE are also not that different from other electrical lighting except for not producing light while producing heat. I'm lights have been left on overnight and do not cause fires...
Make sure it is on a grounded outlet and have a surge protector for your thermostat. Don't plug too many things into that outlet. My assumptions is you are not using some crazy wattage CHE. CHE base can become really hot so not touching anything flammable is a very good idea.
Been using CHE and night incandescent bulbs for over 20+ years keeping all types of reptiles and haven't had a fire.