I sold my 1.1 pair of het pieds to sweety314 and will be shipping them out to her next week. My question is regarding how many heat packs you guys/gals would recommend putting in the box with them. I'm using an insulated shipping box (12"x12"x10" with 1/2" foam) and they will each be in individual deli cups surrounded by packing peanuts. They are going from PA to OR overnight and the high temps are around 60 with lows around 40 in both areas.

I was thinking I'd use 3 40 hour heat packs, two on bottom one on top and open one of them 10 hours or so before they are packed up so that it is already nice and warm while the others start warming up. Does this sound good?