Sunday, December 22, 2019

Comfortably Cold, What’s That?©


 
Photo by the author

I frequently write and teach about the need to stay “comfortably cold” in the winter, and for that matter in the spring and fall as well.

Now, you might be asking yourself, “Comfortably cold, what’s that”?  That is a good question, so let’s talk about it.

The first thing you need to know is that your body is like an engine, you take in food as fuel and you burn it as you move about, work or even when you sit and read an article from The Woodsman’s Journal Online!  And just like an engine, only about 20% of the food energy that you burn is used to do work, the other 80% or so becomes heat.  Like a car’s engine, you also have a radiator, it is your skin!  As with any radiator, the greater its surface area in relation to its thickness, the greater the heat loss and the more effective the radiator.  Because of this your ears, nose and chin; and your arms and legs, and in particular, your hands, fingers, feet and toes are very good radiators: that is why during the winter they get cold and frostbit the quickest.

Now the more work your body does, the more food-fuel you burn and the more heat you produce.  Some of you have probably poured water on an overheating radiator, to cool off a hot engine, this is what your body is doing when you start to sweat: it is pouring water on the radiator to cool off the engine!

 
An excerpt from Naval Arctic Operations Manual: Part 1 General Information, p. 157

But the problem with sweating, is that you get wet.  And during the winter, but any time really, you must stay dry, because water removes heat 32 times faster than air1.  And the cold winter or Arctic air can quickly pull heat away from your body.



 
Excerpts from Naval Arctic Operations Manual: Part 1 General Information, pages 161 and 163

Perspiration in the Arctic or during the winter condenses and freezes as hoarfrost either in your underlayers or on your windproof outer layer.  Once this happens you become cold and hypothermia begins to loom on the horizon!

“Okay, so our bodies are a finely tuned machine, with a large radiator and getting sweaty is bad”, you say, “but what is comfortably cold and how do you get it”? 

Comfortably cold is when you are neither too warm nor too cold, you’re just right, maybe a little bit cool, and you are not perspiring.  You can keep comfortably cold by reducing or increasing your activity level as you become too hot or too cold.  But the best way to stay comfortably cold in the outdoors is by layering your clothes, and by loosening, removing or adding layers as you warm up or cool down. 

Layers of clothes wick away sweat, adjust insulation and protect against wind, rain and snow.  Layering allows you to make quick adjustments based on changes in the weather and your level of activity by adding or removing layers to trap heat or to avoid overheating.  Remember it is always better to underdress and be cool than to overdress, be too hot, perspire heavily, and become wet and then cold later. Also, make sure that each level is sized larger than the one under it so that the clothes fit loosely, because pressure from your clothes, particularly around your joints, will quickly shut off the blood supply to the pinched areas and make it more likely that you will become cold or frostbitten.

There are three layers and each layer has its own function.

The base layer or under-most layer is the most important as it is against your skin and keeps you dry.  Your base layer should be made of wool, synthetics or silk, since these fabrics transport perspiration away from your skin.  Also, these fabrics when wet dry fast. 
Your base layer or underwear can be anything from briefs and a T-shirt in warm weather to long underwear tops and bottoms in cold weather, and long underwear should be the two-piece kind, not the one-piece kind, because they are easier to change if you get either the tops or the bottoms wet.  You under-layer or base layer should fit loosely in warmer conditions to increase air circulation and in cool conditions your base layer should be snug, but not tight or constricting, to keep body warmth next to your skin.

The Middle layer, or insulating layer, helps you retain heat by trapping warmed air close to your body and it should be made of wool, fleece or goose down.  The middle layer is available in three different weights; lightweight for high energy activities or mild climates, mid-weight for moderate activity or moderate climates and heavy-weight or expedition-weight for low activity or cold climates.  It is always better to have two or more light-weight, middle layers than just one heavy one.

The outer layer is sometimes also called, the shell layer, the weather-proof layer or rain gear and is vital in bad weather because wind and water can quickly chill you and KILL YOU!  Your outer layer should be a wind and water-resistant or waterproof layer, to protect you from the rain, snow and wind.  Your outer layer must be roomy enough to fit easily over your other layers and not restrict your movements or make your clothes feel tight.









 
Excerpts from Naval Arctic Operations Manual: Part 1 General Information, pages 159, 161 and 165 to 166

If you are beginning to overheat, remove your hat or if you becoming too cold put on a hat, since heat loss from your bare head can be up to 33% at 60oF (15oC), up to 50% at 40oF (4oC) and up to 75% at 5oF (-15oC)2.  Also, besides removing layers, if you are becoming too warm you can open your zippers and vents or loosen your clothes by loosening the waist belt of your outer-most layer.  If you are becoming cold you can close your vents and zippers and tighten your waist belt.  Don’t remove your outer most weather-proof layer, instead remove your middle, insulating layers and then put your weather-proof layer back on,  Whenever you stop to rest, put an insulating layer back on, under your weather-proof layer, and whenever you begin to increase activity, remove one of your insulating layers.  Bring a pack to put the layers you have removed into, because clothes tied around your waist or on the outside of your pack will get snagged, lost or wet.  The Naval Arctic Operations Manual also has some great tips, which are below.

 
An excerpt from Naval Arctic Operations Manual: Part 1 General Information, pages 161 to 162

But what do you do if you do end up with hoarfrost within your layers of clothes or your clothes have become covered with snow?  You should brush the snow and hoarfrost off your clothes before you enter some place warm.  If you don’t have a brush, you can use a smooth stick to beat the snow and hoarfrost out of your clothes.

 
An excerpt from Naval Arctic Operations Manual: Part 1 General Information, pages 162

 
The author’s whisk broom for removing frost and snow, originally it was an umpire's brush, photo by the author.

And remember no matter what season it is, it is important that you stay dry!  During the spring or fall, and even during the summer, while wet clothes might not freeze, they can still overcool you and cause hypothermia.

 
An excerpt from “Day hikers are the most vulnerable in survival situations”, by Jayme Moye

I hope that you enjoy your next winter trip into the wilderness and I hope that you can stay comfortably cold!

I hope that you continue to enjoy The Woodsman’s Journal Online and look for me on YouTube at Bandanaman Productions for other related videos, HERE.  Don’t forget to follow me on both The Woodsman’s Journal Online and subscribe to BandanaMan Productions on YouTube, and if you have questions, as always, feel free to leave a comment on either site.  I announce new articles on Facebook at Eric Reynolds, on Instagram at bandanamanaproductions, and on VK at Eric Reynolds, so watch for me.

That is all for now, and as always until next time, Happy Trails!


Notes

1 Ministry of Forests, Wilderness Survival, [Ministry of Forests, British Columbia, 1978], p. 46

2 Captain Earland E. Hedblom, MC, USN; Polar Manual, Fourth Edition, [National Naval Medical Center, Bethesda, MA, 1965], p. 37

Sources

Hedblom, Captain Earland E. MC, USN; Polar Manual, Fourth Edition, [National Naval Medical Center, Bethesda, MD, 1965], p. 37, https://ia800305.us.archive.org/33/items/PolarManual4thEd1965/Polar%20Manual%204th%20ed%20%281965%29.pdf, accessed 12/07/2019

Ministry of Forests, Wilderness Survival, [Ministry of Forests, British Columbia, 1978], p. 46

Moye, Jayme; “Day hikers are the most vulnerable in survival situations”, [National Geographic, April 11, 2016], https://www.nationalgeographic.com/adventure/2019/04/hikers-survival-tips/, accessed 12/06/2019

Navy, Department of the, Naval Arctic Operations Manual: Part 1 General Information, [Department of the Navy, 1949, Revised in 1950], p. 157-175,


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