I read the colder the water the body will absorb it faster. Anyhow I went to Academy and got insulated bottle carriers. They are the same plastic bottles, but they fit into a insulated carrying case. It comes with a strap that I cut off, of one, and I left it on, on the other one. I put about 1/4 ice in them with whatever you want to drink and it last for quit a while in the Texas sun. I thought about the CB, but I thought it would put to much weight above the center of gravity.
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George