if gutted, skined, and washed then put in a mesh bag and a deer bag (like a giant pillow) i would say lows in the 60's. i am speaking only of blacktail experience. we have killed them sat morning..proceeded with the above, hung all day in 90 degree heat (under tree in off and on shade), let it sit over night in the 60's. then leave sunday morning and drive 3 hours home and process myself. We have NEVER had one spoil because of it.... but, if you are going to hang you need to make sure it is in a pillow type bag and not a mesh bag.

if you just want to hang it without skinning it, i would not know, but i would say it would have to be much cooler then the 60's i mentioned.