If the inside of your heated camp is a lot warmer then the outside area where you were hunting all day then you're better off to take the primer or cap off and store the rifle in the truck. Just make sure the muzzle is pointed down in case any moisture forms. (Check your regulations... In Wisconsin if the cap is off or the pan is cleaned then they consider the rifle unloaded. Some states do not do that.)

Some people do bring them inside but they wrap them in blankets and let them warm up slow. I have never done that. I am a believer in shooting the rifle off at the end of the day, cleaning it, and then loading fresh in the morning.

Good luck.