Heat Management and Clothing for Outdoor Travel

© 2011 Appalachian Mountain Club

Heat Management and Clothing for Outdoor Travel

Heat Management and Clothing for Outdoor Travel

Clothing for outdoor activities

– Technical clothing helps your body maintain an optimal temperature.



So What Are We Up Against?So What Are We Up Against?

Mount Washington– July 20, 1996 avg. windspeed 100 mph - entire day!-– July maximum typical 54 F, record low 24F

For every 1000 feet of elevation gained the temperature goes down about 5 degrees

Tops of mountains have their own weather – clouds, fog, drizzle sit on a summit even on a perfect summer day


Clothing for Outdoor ActivitiesClothing for Outdoor Activities

THE LAYERING PRINCIPLE– Keeps you warm when it’s cold, cool when warm, dry

when wet, breathes well to keep you dry inside out» WICKING Layer - stay dry inside» INSULATING Layer - traps heat» WATER/WIND PROOF Layer - protection shell

– Know how to use layers effectively


Ways You Lose and Gain HeatWays You Lose and Gain Heat

MECHANISMS OF HEAT TRANSFER – Conduction: contact with cold surface– Convection: wind chill– Radiation: direct sun– Evaporative cooling: sweating, wind


Ways You Lose HeatWays You Lose Heat

Mechanisms of heat transfer:

– Evaporation – staying dry is key to staying warm


A Word about CottonA Word about Cotton

Cotton is dangerous for cool and/or wet conditions:– Cotton absorbs water easily and loses insulating ability!– Stays cold and clammy next to your skin!– Wet cotton conducts heat away from body!!– Wet cotton dries very slowly!!!– Wet cotton can chafe & irritate

CottonCotton=


Wicking Layer - Next to SkinWicking Layer - Next to Skin

Main Function– Wick sweat away from skin – Dries quickly– Keeps you dry

Material– Nylon/polyester


More Ways You Lose HeatMore Ways You Lose Heat

– Radiation: body heat radiates away from us

– Conduction: body heat flows towards cold air or object


Insulating Middle LayerInsulating Middle Layer

Main Function– Trap warm air next to body– Still air is an excellent insulator

Materials– Fleece: great choice– Wool: rugged, dries slowly– Synthetic down: light– Down, like cotton, useless wet



Ways You Lose HeatWays You Lose Heat

– Convection: movement of heat by air or water


Shell LayerShell Layer

Main Function– Blocks wind – prevents convective heat loss– Blocks rain – keeps you dry

Materials– Waterproof, breathable fabric stops rain, moisture escapes through pores– Coated nylon fabric does not breathe

Features– Vents, pit zips– Split sides on pants– Full side zip pants– Pockets– Zip-off extremities


How Does the Shell Work??How Does the Shell Work??

Some Examples:Some Examples:– Windstop fleeceWindstop fleece– SoftshellsSoftshells– ““Transition” by MHTransition” by MH– DriclimeDriclime


ExtrasExtras

Warm hat

Gloves/mittens

Sun hat


What to wear, what to wear?!?What to wear, what to wear?!?

Synthetic T shirt Nylon pants or shorts Hiking socks & boots

Always carry:

Extra synthetic T shirt

Fleece jacket

Rain top & bottom


How it all works together!How it all works together!

What’s needed – weather, conditions, exposure, exertion, hydration, food intake and cooperative group for lots of strip stops.

Attention to your body – everyone is different and has different body temp needs. Layering is an art not necessarily just a science. Play with it figure out what works for you.

Layering system and how you use it is linked to other important aspects of your trip, including safety and enjoyment. Controls comfort and prevents hypothermia and other related health concerns.


In SummaryIn Summary No Cotton – all synthetics all the time on the trail Flexibility Rules

– Have a flexible layering system to keep you warm and dry regardless of the conditions and your activity

– WICK + INSULATE + SHELL– Make sure your layers fit together!

Plan Ahead– Pack extra to ensure you have dry clothes– Your clothing may be your only shelter and warmth if

you’re benighted Keep it dry / Wear it dry


CreditsCredits

Mountain Hardware (Large Photos!) Patagonia Mount Washington Observatory REI Duke University Biological Sciences

Scanning Electron Microscope Facility Sierra Designs NikWax Marmot Gore Corporation Outdoor Research Original slides – John Hazell


Documents

Heat Management and Clothing for Outdoor Travel