Heater in a blind? Dang, I whine about the extra weight when I have to wear two layers of warm clothes rather than just the one. :-p
I had a duck hunting buddy that used to set up a little hibachi grill in his blind. They'd cook hot dogs and stuff while waiting for mallards to come in. Apparently, they stopped after the wind blew their burlap blind material into the grill. The good news is, next to taking a whiz or getting a coffee, nothing is more certain to bring in squadrons of ducks than a burning blind. :-D