[flyyyguy]

taping it to the outside doesnt really add heat per se, but it helps maintain the temp inside, esepcially if using a quality thick walled cooler sealed well. Your circumstance doesnt sound like you need much, so it would be just a little bit of extra insurance to insure you dont stray too far

most convenience stores and hardware stores carry the 7 or 8 hour packs this time of year

A 30 hour inside the cooler wrapped well so it doesnt give off too much would prolly work just fine too


to be honest, usually when I tape heat packs to the outside is when it is super cold....like 20......and I use them inside too. goal is lots of heat, but not lots anywhere near the bags themselves just to help maintain what you started with