I have a unique problem, it think. I sell eggs about every day on a honor system. In the summer i have an electric cooler that i placed the eggs in and the people drop by, put their money in a jar, and take what eggs they buy. Winter poses a problem. The cooler can't be used and they are freezing. Here's my plan, let me know what you think. I plan to build a cabinet and take Pipe heat tape and zigzag on the inside walls. The tapes just keep water lines above freezing. Do you think if i insulate the walls that the heat tape will produce enough heat to prevent freezing? I am in upper east Tennessee and we have alot of mornings in the low 20's. Any suggestions? I work 10 hour days leaving at 6:00 am and returning around 6:30 each evening and I need to keep up the honor system. So far, I haven't lost eggs to greedy people. Thanks!