A cooling vest is a garment worn on the torso that helps regulate body temperature in hot conditions. Cooling vests can be worn for work, exercise and medical purposes. Athletes often wear them before competitions to improve performance. People suffering from multiple sclerosis and other diseases often find cooling vests provide some relief and allow them to be more active when flare-ups of their illnesses raise their body temperatures.
There are two types of cooling vests: active and passive. Both active and passive vests work best when they fit the wearer’s torso snugly. Direct sunlight, humidity and ambient temperature can keep a cooling vest from reaching its optimal effectiveness.
Active cooling vests require a power source to keep cool, and they use the generated energy to keep re-circulating cold water or liquid chemical mixtures throughout the vest’s interior. The energy also keeps the liquid chilled. These vests can run on either batteries or AC power adapters. They sometimes include caps that can be placed on the head, allowing the wearer to cool down more quickly.
More expensive active cooling vests combine portability with effective cooling. These garments are often used by firefighters, military personnel, HAZMAT teams and others whose work puts them at risk of heat exhaustion. This type of specially made clothing is a descendant of the cooling garments that NASA developed for astronauts during the 1960s.
Active cooling vests are made from special synthetic materials that are more conductive to cooling elements, which make them more expensive. The adjustability of temperature settings is one advantage of these specially made cooling vests. Weight could be a consideration, because these vests can weigh as much as 10 pounds, although some weigh significantly less. Despite its effectiveness, the active cooling vest’s power needs make it less suitable for sustained outdoor activity.
Passive cooling vests use ice to keep the body from overheating. These vests have large pockets to hold ice packs that can be filled and reused. This is often one of the less expensive types of cooling vests because of its simplicity. These vests don’t retain their cool temperature as long as other kinds and can lose their effectiveness in as few as 30 minutes. Their portability and low-tech construction, however, makes them better suited for outdoor use than active vests, making “active” seem like something of a misnomer.
Some passive vests use chemical technology to retain their lower temperature for a longer period of time. The phase change cooling vest contains liquids that solidify at higher temperatures and retain their coolness for as long as two hours. These vests require very little time to become chilled again — sometimes a short stint in the refrigerator or freezer will bring them back to full cooling strength. Evaporative vests are soaked in water and often use both the diminishing water’s coolness and pocket ice packs to keep the wearer cool.