© 2011 Appalachian Mountain Club Heat Management and Clothing for Outdoor Travel n Clothing for outdoor activities –Technical clothing helps your body maintain an optimal temperature.

© 2011 Appalachian Mountain Club

So What Are We Up Against? n Mount Washington –July 20, 1996 avg. windspeed 100 mph - entire day!- –July maximum typical 54 F, record low 24F n For every 1000 feet of elevation gained the temperature goes down about 5 degrees n Tops of mountains have their own weather – clouds, fog, drizzle sit on a summit even on a perfect summer day

© 2011 Appalachian Mountain Club Clothing for Outdoor Activities n 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

© 2011 Appalachian Mountain Club Ways You Lose and Gain Heat n MECHANISMS OF HEAT TRANSFER –Conduction: contact with cold surface –Convection: wind chill –Radiation: direct sun –Evaporative cooling: sweating, wind

© 2011 Appalachian Mountain Club Ways You Lose Heat n Mechanisms of heat transfer: –Evaporation – staying dry is key to staying warm

© 2011 Appalachian Mountain Club A Word about Cotton n 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 Cotton =

© 2011 Appalachian Mountain Club Wicking Layer - Next to Skin n Main Function –Wick sweat away from skin –Dries quickly –Keeps you dry n Material –Nylon/polyester

© 2011 Appalachian Mountain Club More Ways You Lose Heat –Radiation: body heat radiates away from us –Conduction: body heat flows towards cold air or object

© 2011 Appalachian Mountain Club Insulating Middle Layer n Main Function –Trap warm air next to body –Still air is an excellent insulator n Materials –Fleece: great choice –Wool: rugged, dries slowly –Synthetic down: light –Down, like cotton, useless wet

© 2011 Appalachian Mountain Club

Ways You Lose Heat –Convection: movement of heat by air or water

© 2011 Appalachian Mountain Club Shell Layer n Main Function –Blocks wind – prevents convective heat loss –Blocks rain – keeps you dry n Materials –Waterproof, breathable fabric stops rain, moisture escapes through pores –Coated nylon fabric does not breathe n Features –Vents, pit zips –Split sides on pants –Full side zip pants –Pockets –Zip-off extremities

© 2011 Appalachian Mountain Club How Does the Shell Work?? n Some Examples: –Windstop fleece –Softshells –“Transition” by MH –Driclime

© 2011 Appalachian Mountain Club Extras Warm hat Gloves/mittens Sun hat

© 2011 Appalachian Mountain Club What to wear, what to wear?!? n Synthetic T shirt n Nylon pants or shorts n Hiking socks & boots Always carry: Extra synthetic T shirt Fleece jacket Rain top & bottom

© 2011 Appalachian Mountain Club How it all works together! n What’s needed – weather, conditions, exposure, exertion, hydration, food intake and cooperative group for lots of strip stops. n 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. n 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.

© 2011 Appalachian Mountain Club In Summary n No Cotton – all synthetics all the time on the trail n 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! n Plan Ahead –Pack extra to ensure you have dry clothes –Your clothing may be your only shelter and warmth if you’re benighted n Keep it dry / Wear it dry

© 2011 Appalachian Mountain Club Credits n Mountain Hardware (Large Photos!) n Patagonia n Mount Washington Observatory n REI n Duke University Biological Sciences Scanning Electron Microscope Facility n Sierra Designs n NikWax n Marmot n Gore Corporation n Outdoor Research n Original slides – John Hazell

© 2011 Appalachian Mountain Club