Extremely hott, this thing will burn you out of your tent and heat your whole home. I wanted to be able to use this in any climate and in the rain and snow so i made a bottom floor plate and attached the intake inbetween the plate and heater housing, i then made a wall seperating the exhaust from the intake tube and filter, i made extended "weather shields" the extend out and protect the inlet and outlet air and electronics muffler exhaust etc. I also put some rubber feet on the bottom to help keep it in place and secure on the ground or roof or wherever. I attached a quick disconnect for the power wires and a long cigarette plug, i also moved the fuse inside of the housing and added wire clamps.I also got exhaust heat shield wrap to cover the exhaust but its really not needed, the exhaust on full blast still doesn't get too hot. I feel safe putting this on dry grass and not worrying about any fires. I used aircraft aluminum and hardware for all upgrades.