Never heard of propane freezing. If they can smell it, they can smell you so it wouldn't matter either way. I've never had a problem. It only seems noisy because you are in an enclosure hovering right over top of it. They can't hear it a few feet away, especially if it's closed up good and insulated. The heaters are supposed to have an automatic shutoff when oxygen levels get low but never trust them and take a knap while it's running. It was 22 degrees the last time I got in the blind and fired up the heater. It took about 10 minutes to get it to 68 with just a single burner cheapo from Walmart.