Has anyone had any success with any type of 'cooling' clothing?

Hey guys I am trying to plan a family vacation to calif the end of this month. I know it is going to be very hot and to say I am nervous would be an understatement. Someone (without ER) suggested trying some 'cooling clothing' that is designed for the people that have to work out in the extreme heat. After doing some research I found they make several different types of things that are intended to cool your body temperature. They make vests, head bands, wristbands and even anklebands. Some of them actually have those gel packs that you insert inside the vest and supposedly keep you cool down to 52 degrees for up to 4 hours. I also found that they actually make some clothing specifically designed for people with MS. Apparently MS patients have symptoms that are also triggered from the heat. I actually saw places where insurance companies are paying for MS patients to have these sort of devices. So anyway, I have two questions:

#1- has anyone every used any of these types of devices? How have they worked? Are there any that you can specifically recommend?

#2- Does anyone know if insurance companies are willing to cover these type of devices for people with EM?