I run one in my blind and it's sealed pretty tight. I usually have one or two windows cracked and after I get some heat in the blind the windows stay pretty clear. I set all day before sun up to after sun down and the one thing I don't like to be is cold, so it's pretty cozy in the blind. No gloves or coat needed and I made a stand that sets over the top of the heater and works like a stove. I have a small pan that easily holds a can of soup, stew, or any left overs and having something hot with a sandwich is pretty nice on a cold day.