i bought some caribou game bags and they came with plastic bags and tie wraps to put the meat in and then put the meat in the game bag...isnt this a no no because the meat wont be able to loose heat

hmmm.....the caribou bags I bought didn't come like that. They're just synthetic bags with draw strings and reflective tags on them. No plastic bag (other than the carrying case ) nor did any tie wraps come with the package.

I'd avoid using the plastic for sure, unless you're only using it to keep your pack from getting bloody on the pack out. Once you're in camp or have them in the pickup bed driving home, let them breath...

Wrapping in plastic is bad news. Carrying meat in a waterproof pack is equally bad but something that usually needs to be done. Get it out in the air as soon as you can.