Thought I would add - my husband is a very dedicated golfer and plays in temperatures up to 115 degrees. To do so successfully, we take several steps to prepare starting with freezing half-full water bottles. (I put the top half in the coffee pot reservoir). My husband carries a 5 or 6 of these in an insulated pouch of his golf bag then uses a large thermos (pre-cooled) which holds about 100 ounces of water which he uses to fill the iced water bottles out on the course. He also has a hat and towel made of a special fabric that he soaks in a bucket of water for a couple hours or so before using and these stay cool for several hours. After squeezing them out a bit he puts the hat on his head and towel around his neck. He does get a bit wet from these but I much prefer he be a bit of a mess than have a heat stroke! He also buys additional water as needed out on the course. It doesn't sound like much fun to me but he plays weekly with a group of guys who really look out for each other - anyone not acting quite right its back to the clubhouse in a hurry for all of them.