When I hunt when it is warm out I take 3 1/2 gallon milk containers that have been filled with water and frozen. It keeps my lunch cold and if I get a deer I use it to cool down the deer. If I shot a deer in the evening and cannot get it to the processors till the next day I use 5 bags of ice and wrap it up in a tarp which is tied tightly closed and placed on the floor. 12 hours later the ice is still not completely melted. No peeking though, it lets the cold air out.

HH