Sorry, I read that as room. I believe they would be too much for a tent. That said, I have seen a few people using a low profile plate heater that may actually be an oil filled radiator, just smaller for inside the tent. Very small footprint and very low fire hazard.
ETA: Something like this
NewAir Portable Heater - 400-watt Under Desk Heater with Slim Fit Design and Silent, Energy Efficient Operation | Ideal for Office, Desk, Home, and More
https://a.co/d/75RPEhO