1Dmk2 owners : What do you do about your battery in the COLD?!

Hey guys-
Yes I know I could post this in the 1dmk2 / 1dmk2N thread, but it would get burried so fast by airplane and cat pictures that I figured i'd get more of a response here. Last year whenever I shot in the cold I could hardly keep my battery alive. I know it's NiMh and not Lithium which is extremely effected by cold temperatures, but would like to shoot a bit more.

Does anyone have a fix for this? besides bringing 3 extra batteries wrapped in a heat blanket or something? I'd love to hear what other shooters are doing. thanks guys!

I don't shoot much in extreme cold, but what about using those hand warmers (Coleman makes some, found in the camping section of stores like Target), maybe taping them to the grip.

I'm bringing this thread back to life, anyone have any ideas? I need to purchase a new battery while im at it, any suggestions?

How cold is your cold? I've shot 6 hours in temps 10 - 20F. Need more? I'd put the spare inside my jacket, that would get you 12 hours. Below 10F? I dunno, never shot more than 3 hours down that cold. (keep your "IS" off)

those hand warmer chemical packs

i didn't know IS drained more battery, good to know. I think i need to order a lenmar or another battery...amazon's the best place right? I have 2 additional batteries and even after a refresh they still blink NO POWER upon insertion. weird...

Last winter I took 2000 shots outside and in hockey rinks with my 1D Mark II. No problems really. How old are your batteries? Canon or 3rd party?