OAUSA Net - August 16, 2018 - Keeping Cool Outdoors

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DaveK
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OAUSA Net - August 16, 2018 - Keeping Cool Outdoors

#1

Post by DaveK » Wed Aug 15, 2018 12:29 pm

KEEPING COOL OUTDOORS

If you have listened to our nets, you know that we believe in "comfort camping." This is not to say that we hold comfort above all else, but when vehicle space permits and the cost is reasonable, then we most certainly give serious consideration to any new idea that pops up. Summer time, and the heat that naturally accompanies this season, keeps us on the constant prowl for a means to keep cool.

Paul, KK6DYO, being the skilled inventer he is, has a solution that might become a permanent part of your camping gear, especially when the temps start rising. Join us for a discussion of a most unique solution to hot summer nights (and days too!).
DaveK
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Extremism in the defense of liberty is no vice.
Moderation in the pursuit of justice is no virtue.

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KK6DYO
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OAUSA Net - August 16, 2018 - Keeping Cool Outdoors

#2

Post by KK6DYO » Wed Aug 15, 2018 7:06 pm

I love being outdoors, specifically in the desert, but hate the limited seasons during the year. The desert is essentially off limits from mid-Spring through mid-Fall. Just too hot during Summer days, though the nights can be very comfortable.

For decades I've been trying to "stay cool outdoors". I've come up with a few things that sort of work, but no real solutions, other than to mostly avoid being outdoors during six months of the year.

I'm hoping that others have discovered techniques and practices that work for them, and are willing to share them as we together trying figure out how to stay cool outdoors.

The temperatures for Borrego Springs might be considered typical for a desert.

Borrego Springs, California average temperatures
BorregoSpringsTemperatures-85.png

Recent day's temperatures at Anza Borrego
AnzaBorregoDay.png

While humans can acclimate to temperature extremes, we're mainly confined to a 10° range of comfortable temperatures, depending on humidity.

Badwater, Death Valley to Whitney Portal Ultramarathon

Comfort range: temperature v. humidity
Comfort.png
Comfort.png (71.77 KiB) Viewed 102 times

One idea of comfort
Motorhome.png

I doubt one can stay truly cool, so perhaps this net should be called "How to Avoid Dying in the Desert". The following chart shows combinations of temperature and humidity that can lead to dangerous and possibly fatal heat injuries, which we'll look at in more detail later.


Comfort, discomfort, danger of heat injury
heat-index-chart-relative-humidity-2-802x449.png

Heat index is a fairly complex calculation that uses temperature in the shade, and doesn't take solar radiation and air movement (wind velocity), critical to an overall comfort determination.
Last edited by KK6DYO on Thu Aug 16, 2018 3:29 pm, edited 4 times in total.

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Thermodynamics

#3

Post by KK6DYO » Wed Aug 15, 2018 7:07 pm

https://en.wikipedia.org/wiki/Thermodynamics

First law of thermodynamics: The internal energy of an isolated system is constant.
You must transfer energy (heat) to become cooler.

Second law of thermodynamics: Heat cannot spontaneously flow from a colder location to a hotter location.
If it's hotter outside than you are, it's tough to get cool.

Ways to transfer heat
HeatTransfer.jpg
Last edited by KK6DYO on Thu Aug 16, 2018 3:36 pm, edited 2 times in total.

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Human Body

#4

Post by KK6DYO » Wed Aug 15, 2018 7:09 pm

Our primary mechanism for transferring heat is perspiration
2.6 million sweat glands on average
HumanBodyResponse.jpg
HeatTransfer2.jpg
Last edited by KK6DYO on Thu Aug 16, 2018 4:08 pm, edited 2 times in total.

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Dangers

#5

Post by KK6DYO » Wed Aug 15, 2018 7:12 pm

Heat Index and Potential for Heat Injury
And note that heat index in calculated for the shade, not accounting for solar radiation
HeatIndex.jpg

Heat Injury Symptoms and Treatments

Note that Heat Stroke is a medical emergency!
HeatInjury.jpg

You must avoid heat injury by keeping cool
Last edited by KK6DYO on Thu Aug 16, 2018 3:47 pm, edited 1 time in total.

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Hydration

#6

Post by KK6DYO » Wed Aug 15, 2018 7:12 pm

Water


Sports Drinks
  • Enhances absorption of fluid more than water alone
  • Sugar content higher than body fluid so difficult to absorb
Caffeine
  • Diuretic - can increase non-sweat water loss (urination)
  • Can increase heart rate
  • Can increase blood flow to skin

Alcohol
  • Diuretic - can increase non-sweat water loss (urination)
  • Inhibits hormone that regulated fluid balance
  • Depresses hypothalmus which regulates body temperature
  • Can increase blood flow to skin
Last edited by KK6DYO on Thu Aug 16, 2018 4:07 pm, edited 1 time in total.

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Clothing

#7

Post by KK6DYO » Wed Aug 15, 2018 7:29 pm

Africans.jpg
The risk of Sunburn has to do with the melanin in your skin. Dermatologists rank all of us in a skin pigment level depending on your melanin level. Melanin is the pigment in your hair, skin and eyes that give color. Those with lighter skin have less melanin than those with darker skin.
  • Type I: Pale white skin – always burns, never tans
  • Type II: White skin – Burns easily, tans minimally
  • Type III: White skin – Burns minimally, tans easily
  • Type IV: Light brown or olive skin – Burns minimally, tans easily
  • Type V: Brown skin – Rarely burns, tans easily and darkly
  • Type VI: Dark brown or black skin – Rarely burns, always tans, deeply pigmented
The Thobe
How hot does a thobe get?
Thobe.png

Bedouins wearing black
Why do Bedouins wear black robes in hot deserts?
We report here that the amount of heat gained by a Bedouin exposed to the hot desert is the same whether he wears a black or a white robe. The additional heat absorbed by the black robe was lost before it reached the skin.
BedouinMen.jpg

Sun Protection Factor (SPF) versus Ultraviolet Protection Factor (UPF)
SPFvUPF.jpeg

SPF is for subscreen
SPF.jpeg

Neutrogena UltraSheer Liquid SPF 70
Meateater - Wear Sunscreen
NeutrogenaLiquid.png

Ultraviolet radiation: UVA, UVB, UVC
ABCsofUV.png

UPF is for clothing
UPF.jpeg

Clothing Material
Light color (reflective), breathable, wicking, light weight, loose
Cotton, polyester, or mix?
Virtually all of my "wicking" polyester is not breathable to uncomfortably sticks to my sweating body


Clothing Label
ClothingLabel.jpg

Shirt
CoolDriT.png

Columbia Tamiami Shirt
UPF 40, 100% polyester, wicking, mesh-lined venting in back
TamiamiShirt.png

Pants
Pants.png
And did you also want that in camoflage?
Last edited by KK6DYO on Thu Aug 16, 2018 6:42 pm, edited 6 times in total.

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Headwear

#8

Post by KK6DYO » Wed Aug 15, 2018 7:34 pm

Wide brim, light color, light weight, well ventilated, wicking sweatband, chin strap, dark underbrim, stylish!

Stetson Coffee Tab Outdoor Hat
StetsonOutdoor.png

Stetson Costner Vented Jute Outdoor Hat
StetsonOutdoor2.png

Dorfman Pacific Soaker
DorfPacSoaker.png

Tilley AIRFLO
Tilley.jpg

Shemagh
Shemagh.jpg

Adam's Headwear Extreme Condition Hat
AdamsHeadwear.png

Vaqueros
Vaqueros.jpg

Kool Breeze
KoolBreezeHat2.png

Ghutra
5 Ways to Wear Your Ghutra
Ghutra.png

Mission Tech Knit Hoodie
MissionTechknitHooodie.jpg

Sun Umbrella
SunUmbrella.png
Umbrellas.jpg
Last edited by KK6DYO on Thu Aug 16, 2018 6:44 pm, edited 7 times in total.

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Footwear

#9

Post by KK6DYO » Wed Aug 15, 2018 7:44 pm

Merrell Moab 2 Ventilator
MerrellVentilator.png

Keen Newport Hydro
KeenNewportHydro.jpg

Socks
Duluth Trading
DuluthCoolMaxSocks.png
Last edited by KK6DYO on Thu Aug 16, 2018 4:22 pm, edited 2 times in total.

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Eye Protection

#10

Post by KK6DYO » Wed Aug 15, 2018 7:46 pm

  • Sunlight (UV) protection - polycarbonate blocks 99.9%
  • Safety - especially if shooting (ANSI Z87.1)
  • Scratch resistance
  • No distortion
  • Light weight
  • Anti-fog
  • Comfort
  • Polarized?
  • Prescription?
  • Stylish!
Dark Smoke Lens Shooting Glasses $7.23
Glasses.png
Last edited by KK6DYO on Thu Aug 16, 2018 5:06 pm, edited 2 times in total.

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