The dog days of summer may be winding down, but in this profession, we'll still face a lot of heat-related problems during winter. To combat these problems, we should continue do whatever it takes to reduce the heat load on our bodies. This includes drinking plenty of liquids and taking frequent rest breaks to recover.

Another thing we can do: Use a cool vest when conditions allow—during overhaul of a fire or while in a hazmat suit, for example. But what is a cool vest?

A cool vest is a garment similar to an ice vest. The big difference: The cool vest uses pouches filled with a chemical compound—instead of water—that "freezes" (or goes through a phase change) at 65 degrees F rather than at 32 degrees F.

A cool vest offers many advantages over an ice vest:
- The phase change at 65 degrees F means you can "freeze" the pouches in a small chest of ice water instead of a freezer;
- Ice causes the skin and blood vessels to constrict, trapping heat in the core of the body, whereas the cool vest's 65-degree temperature won't cause this reaction; and
- It's lightweight.

These vests work well. A few years ago, I evaluated cool vests prior to purchasing them for my employer. A 54" piece of pipe had to be heated to 550 degrees F, and a worker had to enter the pipe to weld at that temperature. The air temperature in the pipe was over 130 degrees F, but with the cool vest, the worker was comfortable in the valve body.

To check out some cool vests online, visit www.texascoolvest.com

FireRescue Technical Editor Scott Cook welcomes reader feedback, and invites you to contribute your notes to his column on firefighter ingenuity and street wisdom. You can reach Scott by e-mail at scott.cook1@sbcglobal.net.