Thanks for the input castle-rock-clown! I will usually stay in a spot for 5-10 minutes, if fish are not located. Once I find a school if fish, I have sat on them from 5 minutes to 2 hours depending on the bite. I usually bring a heater as my past shelters were not thermal. I was considering the thermal, from the standpoint of potentially not having to bring my heater and to save on space and weight. The real question is by buying a full thermal will a heater still be necessary? If its still necessary for those cold days, then I will go the cheaper route.