roadrunner
WKR
I freeze 20oz and 1 litre bottles full of water. I take 2-3 48 quart coolers full of these on hunts. I use a 3rd, much larger cooler, for my meat. I place a few at the bottom of the large cooler, add a layer of meat/quarters, then more bottles, etc. Once the meat is cooled down from the first group of bottles, I remove them as many will be partially or all the way melted. I then repack with the second cooler of bottles and hold the meat for days. It keeps the meat dry and cold. I have kept a quartered elk this way for 8 days in 40-70 degree temps.
In very warm temps, I also keep gallon zip lock bags in the event I need to put more ice on meat. I firmly believe that keeping water off the meat results in better meat at the dinner table.
This. Remember, heat energy flows from high to low, so the ice is absorbing the heat from the meat. This is why a hot stove burns you. The more you can layer ice and meat, the better off it is because you draw meat core temp out from two outside surfaces.
As you drain loose fluid (water), you remove cooling material. Keeping it contained keeps the cooling ability in place. Once the total "system" is in equilibrium, it will maintain that temp, which will be somewhere in the the 40's until you get home.