are heat rocks safe for cabinet grows?

now that winter is here im worried about my cabinet getting too cold
should i use a heat lamp or bulb that i could set on timmers to keep it at a safe temperature
or could i use a heat rock i have
it stays a pretty warm temperature never getting too hot to the touch so i figured i could just lean it against the wall near the inlet fan would this be a fire hazzard?

like a reptile heat rock? If so, they tend to crack and really fuck shit up. Lost a 9 month old Savannah Monitor to a hotrock. Go to your local pharmacy and get directed to the heating pads for backs, etc. They are hell of a lot cheaper than a "seedling mat". Probably won't satisfy your chill issue though. What kind of lighting are you using?

yes a reptile heat rock and thanks for the input a heat pad sounds like it would help alot and im going to be using cfl's
i plan to use the cold nights as the lights on time if i can keep it at a good temperature and lights off during the day but not sure if that would work since it should be colder at lights off if im correct my bookshelf is almost done im going to put the fans in soon and monitor the temp and see what im getting, hope i can figure somethin out i dont wanna have to wait till after winter since it gets hot in texas and ill have to figure out somethin to keep them cool