Thanks for the info on the Auto Cool, guys. I guess I won't run out and buy one.

Re: heat + water in plastic bottles.

I drove from SoCal to Organ Pipe Cactus National Monument in AZ, near the Mexican border. In August. The temp was 112F six feet off the ground. I had two gallons of drinking water (partly frozen) in an ice chest, and six more (soft cloudy plastic like milk bottles) just sitting in the trunk of the car. By 7p.m., the dog and I had drunk all the cold water. I opened one of the other ones, and it was almost too hot to hold onto. I took a sip...

BLEEEECK! It tasted like liquid plastic. Even the dog wouldn't drink it. So, I had to drive to the visitor center and fill up at their machine.

But I have remembered that when I think of storing water in hot weather, esp when traveling (it doesn't get that hot here in WA).
Difficult choice: drink plastic water or die of dehydration?

Sue