Cooling Vests will keep you cool, but different vests are suitable for different situations.
1. Evaporative Cooling Vests are best suited for use outdoors, and on days when humidity is not to high. These vests work on accelerating your body’s natural evaporative cooling. The vests are soaked in water. As the water evaporates your body temperature is reduced.
These vests are relatively effective. They are cheaper than other vests. Prices start at about $30.
On the downside they are not suited to being worn underneath other clothing. This will slow down the evaporative effects. Your clothes will be wet after wearing these vests.
2. Phase change vests these vests use packs that you freeze. The pack is filled with a gel made of Hexadecane. The pack melts at 18 degrees. The high melting point is very effective at keeping your body temperature at a natural level. These vests are very effective indoors and outdoors. They do not really on evaporation to keep you cool so are fine to wear under clothes. You will stay dry.
The only problems with these vests is that they are expensive $180 plus. In addition to this you will need two or three sets of packs to get you through the day costing around $100 plus per set.
3. Personal Ice Cooling System (PICS) are the most effective by far. They are also the most expensive about $1800. They work by pumping iced water around a vest using a small pump. The pump is powered with rechargeable batteries. The water is cooled by ice packs. One of the advantages is that it uses regular ice in packs and as long as you can find a freezer or ice your in business.