Emergency blankets = heat retention - Well hit me with your rythm stick, here I thought I was being so damn smart. Ok, so thanks for the heads-up I put a couple digital therms in there, one on the bottom and one almost on the top and left it sealed with lights on overnight.

Top of box is a balmy 27c and bottom is steady @ 23c...and I haven't even cut open any vents to dissipate the heat yet. Looks like I may be ok...but you had me worried there for a while.

PS: I've looked at all the home reno stores, wally world and not only cannot I find any mylar to buy, all the clerks that help me look for it have never even heard of it before! What's mylar? Uhhh, it's like aluminium foil only different!?! lol