Maximizing cool clothing strategy for hot, dry, sunny desert?

[Chris Hunkeler]

My take on the whole desert clothing thing can be found at my Flickr link below. Scroll all the way down to the credit at the bottom for the link to the article that inspired me.

[Alex H]

Great info Chris, thanks!

[shane c]

Yes, really good, Chris, thanks for sharing.

[Nick Gatel]

Some thoughts on deserts…

I’m not an expert on Bedouins and other nomadic peoples, but historically they have mostly been herders needing water and grazing for their animals, so in summer moving to better locations in terms of climate, elevation, water, and grazing plants is probably the norm. Just like the native Indians that once lived off the land in my location, who moved up into the local mountains in summer.

I don’t do much desert backpacking in summer, unless it is a really great adventure. I can hike in extreme heat, but it isn’t fun, so there has to be a good adventure for me… such as observing bighorn sheep who are forced to seek water often in places with limited sources. I do a lot of early morning short day hikes in the foothills in summer, but most of the time I cheat and go to higher elevations. Most of my summer backpacking is in mountains where it is cooler.

The difference between 95F and 105F is significant. That 10 degrees more than doubles my water requirements. Above 110F most people feel like they just walked into a literal blast furnance. Above 115F you can’t stand in the sun for more than a few minutes, you feel like your body is cooking in an oven, and the top of your feet will get too hot to bear — you have to keep moving or seek shade. Above 120F it becomes nearly impossible to walk very far. We don’t check the temperature each day at home, we have things to do and they need to be done irregardless of the temp, and we don’t want to sit indoors all day. There’s a thermometer on our patio wall and when I take a break sometimes I’ll look at it and the humidity.

Of course not knowing or paying attention to the forecast can lead to poor planning, as it did last year on the first day of summer.

For most people it really is best not to hike in deserts when temps go above 100F. There are some places where it might be a better idea — say hiking to the bottom of the Grand Canyon in summer for some people like me, instead of trying it in winter when there might be a lot of snow in upper elevations.

[shane c]

This may be of interest to some…

http://jap.physiology.org/content/114/6/778

Evaporative cooling: effective latent heat of evaporation in relation to evaporation distance from the skin

[Jerry Adams]

Interesting article

cooling is best when you don’t wear anything and evaporate from skin

about 20% loss in cooling if you have a wet base layer and a permeable outer layer

about 60% loss if you have a wet outer layer and no base layer

worse if you have a wet outer layer and a base layer

[Nick Gatel]

As I stated earlier, my main goal is cooling not reducing perspiration or water intake, thus my preference to hike in only thin running shorts with no liner or no underwear. But for most people hiking in hot deserts this isn’t a smart choice as clothing is need to protect the skin from sun exposure and it becomes a complicated balance between weight, protection, and evaporation. For most the best option is not to hike in deserts when temps exceed 100F. In low deserts that would limit the hiking season to mid October thru mid May, a nice window of 7 months hiking opportunities.

[Anonymous]

Agree it’s interesting Shane and Jerry.  But it’s not fully applicable in desert type conditions. Especially so in not accounting for Solar heat gain. Even if you have darkly pigmented skin and can handle intense UV–it’s still cooler to try to reflect that Solar energy with a very light colored shirt and pants.

In lieu of the article and the research of same, I’d might modify my previous recommendation a little. Wear a fishnet baselayer, and then a loose fitting, stiff fabric partial poncho over same instead. But if you’re cutting out the dark colored baselayer, then you have to go with a more tightly woven fabric poncho because of UV.  And now you would have to also wear arm sleeves as well.

Btw Shane, I don’t have much of an opinion of your cotton washcloth idea either way.  I’d say, try it and see if it works and/or if you like it or not.

[Jerry Adams]

maybe just wear a base layer that reflects sun and protects from UV

maybe that article says it’s better to have a tighter fitting base layer than a loose fitting garment, counter to Beduin robe

[Nick Gatel]

Well there is a lot of theory, then there is what really works for people who actually do these things. Typical uniform here for roofers, gardeners, and people who work outdoors all day is a hat, bandana over the back of the neck, long sleeve white shirt, and long pants. You have to have freedom of movement and not overheat at the same time.

[shane c]

This report reminded me of too loose shirts that get wet from sweat when wind or movement has them periodically contact wet skin directly, and are then very cold to the touch, but do little good cooling wearer when next they are billowing away so far from the skin.

 

[Anonymous]

Difference is that the Bedouins are also accounting for intense Sun and the article researchers aren’t.

Also humidity or lack is a big factor.  Did they test for a wide range of humidity and it’s effects?  I know from my own direct, repeated experience that what I can wear in the tropics to feel more comfortable (rather, slightly less horrid), is rather different than what I can wear here, or even more so verse a very dry desert clime.

There have been research done which shows that generally, people prefer the feel of natural fibers (minus scratchy wool) over synthetics, but at the same time, dry fabrics feel more comfortable than wet feeling fabrics on the skin.

You can wear all cotton and linen in dry desert and rarely experience the clothing feeling noticeably damp. In my area where humidity is commonly between 50% to 85% and above 80 F most of the time, I can’t wear cotton in the heat, because it becomes a sopping mess, especially if I’m doing anything active. The fibers swell with water and it becomes less breathable, takes a long time to dry.  Linen is definitely better than cotton, but still not ideal once the humidity starts going up past a certain point.

Even worse when I’ve been to tropical and sub tropical areas in relation to cotton.

Conversely, when I’ve worn all polyester (most form fitting) in the dry desert, it didn’t feel near as comfortable as the 55% linen and 45% cotton blend, loose, oversized, buttom up shirts.

So I don’t think the researchers in the article are accounting for all pertinent variables that can help or hinder staying cool in various different climes–like Solar heat gain, extreme range of humidity, etc

[Nick Gatel]

Keep in mind the best reason for a shirt is protection from the sun, not cooling strategy. A slight breeze hitting a wet shirt sure feels nice. If your shirt is soaking wet it takes quite a bit of wind to billow it away from your skin, and that kind of desert wind, blowing sand and dust is a bigger problem.

[Anonymous]

For something very different, and not something that I recommend to others at all, though I do find the below very interesting:

Some years back, Wim Hof did a 42K run/walk in hot desert, wearing just a pair of shorts and sandals, with no food or water the entire time (he had some before he started).  He’s most known as the “Ice Man”, and having something like 26 world records (most of which deal with extreme cold temps/conditions), but he thought he could apply similar principles to the desert.

Turns out, he could and did.  The below is a short video of him talking to the people following and researching him while doing this 42K desert endeavor (he’s Dutch):

Again, I don’t recommend it at all, but I do find it quite interesting what he has been able to do. Keep in mind, while he’s quite acclimated to extreme cold, he’s not acclimated well to extreme heat conditions.
Consciously affecting his immune system while injected with E Coli bacteria was pretty dang interesting as well.  (Researchers at first thought he might be a genetic freak in this area, but later on they replicated similar results with a group of people who had been trained in his method).

[Author]

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