Heat Transfer

Heat Movement Heat always moves from warm to cold. Your body loses heat it doesn’t get cold. To stay warm you must stop heat loss 3 Ways Heat Moves Conduction Convection Radiation

Conduction Heat moving through materials Good Conductors: Metals, water, ground Poor Conductors (Insulators) Air, wood, plastics, straw, Closed cell foam, dry organics

Conduction (continued) Avoiding heat loss through conduction: Sleeping Get off of the Ground Tools Don’t touch metal handles Hands Wear gloves (water proof) Feet Thick soled boots on ice Stay Dry

Convection Heat causes materials to move Warm air rises cool air falls Must stop cold air from circulation next to the body Cinch Straps and Draw Strings Sleeping Bags Coats Gloves Convection Destroys your natural warm air blanket

Convection (continued) Convection Ovens Forced air furnace Vent placement Cold air return Ceiling fans Vents in houses and ice houses Dead Air Spaces

Radiation Heat moving through empty spaces (photons) Heat from sun Heat from a fire Need to warm both sides Dark materials gather more heat Most winter clothing is a dark color You are all beings of light and brighten up my day Infrared cameras sense radiant body heat

Radiation (continued) Gather Radiant heat Dark clothing, Ice houses, shingles Reflect heat back to body: Space blanket, white on inside Altitude increases effect (less atm) Sunburn Snow blindness

Heat Loss Prevention Stay Dry Sweating makes you wet and then dries your skin out Stay off of the ground Stay out of the snow Cover head and extremities Air is a great insulator Layer Clothing

The End