Another Way to Beat the Heat

If it seems that I am writing a lot about surviving summer weather, it's because I started a new job about a year ago that has me working outside a lot more than I'm used to. Between the sun, humidity, and working in areas with no airflow, this year has made me dig out all of the tricks and tools that I've used over the years in order to stay cool. Today's trick is a high-tech bandanna.

Several years ago, I was given a funny looking piece of cloth to wrap around my neck in the summer. It looks like a bandanna, but it's actually a closed cotton tube filled with beads of methylcellulose, which is a hyrdrophillic (water-loving) powder made from plant fibers, commonly found in the drugstore as a cure for constipation. It absorbs water and swells, forming a gel that feels slightly slimy to the touch. One specific type that I worked with (we used it as a gelling agent in cosmetics) would absorb 16 times its own weight in water, so it can trap quite a bit.  It's also used as a food additive, so it's safe to have in contact with your skin. 

The one I have now is a MiraCoolbrand cooling bandanna, and I've used it off and on for about three years; the first one I had lasted for five years before the filling finally got washed out by repeated use. It's very simple to use: you just soak it in cool water for about 10 minutes and then wrap it around your neck. The water evaporating from the cotton outer shell keeps it cool, and placing it on the back of your neck helps cool your head. The methylcellulose stays (mostly) inside the tube once it swells up to a size larger than the weave of the cotton, but the water can wick out and evaporate to provide the same effect as a swamp cooler.

Also like swamp coolers, they work best in areas with low humidity but can provide some relief in moderate humidity. In high humidity they do tend to get warm since the water isn't evaporating very quickly, but they still absorb some heat from your neck.

I have used mine for a full 12 hour shift and not had it dry out. I soak it every morning that I'm going to use it, so I don't know for sure how many days it would last on a single soaking, but I've hung it up to dry when I'm not using it and it takes at least four days to be dry to the touch.

They are cheap, effective, simple, and require no batteries; they also take up very little space when completely dry, about as much as a normal bandanna would. 

If a cooling bandanna isn't enough, there are vests that use the same material and work the same way. I have tried the MiraCoolEvaporative Cooling Vest, but I don't care for it because of the weight: I started off with a vest that weighed about four pounds, and then it absorbed another five or six pounds of water. It did keep my torso cool, but the added weight over a 12 hour shift was more than I wanted to deal with. My Camelbak water carrier weighs less and doesn't cut off the air to my skin. The slimy feeling over my entire torso was another downside, but it washed off easily. Being a lot larger than a bandanna, it also takes at least a half-hour of soaking to get a vest ready. 

In digging for links, I've found that the same company is now making ranger/booniehats with built-in tubes of methylcellulose in the crown. If I hadn't just purchased a good straw hat for this summer, I might be interested in trying one out. There's always next year, I hope.