Soo umm that can't be good...

[redshift]

Sucks to find out that way, but it's especially of concern for the pilots. The flyers seem to have many tricks to warm them up, even if it's just sticking it in your pocket for 15-20 minutes. The preheat temps don't need to be any higher than 100F, or 38C, and should not be allowed to drop much below about 80F, or 26C.

Put em in warm and rap on them, as long as the load is consistent they'll maintain their temps. IF they aren't in a case.
Keep in mind with non-hardcased packs you may be able to jump ~1000 mah for the same pack dimensions- that's a GOOD thing...

Good luck!