1. Sleep…..ZZzzzz
Adapted from Polly Anikeeva, Christiaan Adams, Leah Krieger & Mammut sleeping bag guide
Death valley: Dan Duriscoe, U.S. National Park Service
Kitten: cutecutepics.com

2. Why sleep? Benefits of a good night’s sleep, the next day:
Improved resistance to low temperatures
Improved coordination
Improved judgment
Improved overall happiness
(Though night hikes/skis are fun!)

3. Heat loss convection conduction Cold Air radiation You (warm)
breathing
You (warm)
evaporation
conduction
snow/ice/ground = Heat Sink!

4. Sleeping bag reduces convection; Pads reduce conduction
Cold Air
convection
radiation
Sleeping bag fill
reindeer fur, camel hair, Ceiba fruit (kapok), goose underfeathers (down), extruded plastic (synthetic fluff)
goes here
“loft”
breathing
You (warm)
evaporation
pads go here
conduction
snow/ice/ground = Heat Sink!

5. Sleeping Pads Heat loss to the ground is critical
Use 2 or 3 pads on snow!
Types:
Closed cell foam (blue, thin, etc.)
Ridge Rest (MITOC rentals)
ThermaRest (“self”-inflating)

6. (Winter) sleeping bag anatomy
Cinch Cord
Draft collar w/draw cord
Top
Main zipper
Bottom
Expansion zipper 2x ≠1
Layering bags doesn’t work!
Footnote: I’ve done the experiment, so you don’t have to… brrrr
Hood
Draft tube

7. Sleeping bag temperature ratings: How much insulation will you need?
Manufacturers’ rating systems vary by 33°F (18°C) for the same bag!
Also, sleeping bags do decline with wear/use.
Comfort = Survival. Personal needs (heat output & loss) vary a lot
nutrition (you’ll be much warmer on a full stomach)
hydration (drink water to maintain heat output)
fatigue (you’ll produce less heat if you’re exhausted)
your age (heat output varies dramatically)
number of people in tent
gender (women tend to need slightly more insulation than men)
physical fitness, body size & shape, and conditioning
alcohol lowers your core body temp. at the same time that it makes you feel warm- leading cause of hypothermia deaths!
MITOC has a range of bags from x to Do not take those ratings as gospel. If you’re camping in the backcountry for the first time in the Whites, I’d recommend starting with one of MITOC’s warmer sleeping bags and going from there by trial and error

8. Sleeping bag temperature ratings: How much insulation will you need?
MITOC has bags from “+30°” to “-15°”.
Only the “0°” and “-15°” bags are winter bags.
New to winter camping?
Start with the warmest available bag (“-15°” at MITOC) for the first few backcountry (tent) trips!
MITOC has a range of bags from x to Do not take those ratings as gospel. If you’re camping in the backcountry for the first time in the Whites, I’d recommend starting with one of MITOC’s warmer sleeping bags and going from there by trial and error

9. Get ready Sleeping bag use
Get Warm - eat (fuel for the fire!), drink (water), exercise
Get Dry – dry skin & base layer
Wear/bring in damp clothes with you to dry *
Get Dressed –
minimum: base layer top + pants, balaclava/hat, & socks/booties
extra for warmth: fleece top + pants if needed
avoid constriction- loss of loft (no insulated parka!)
*Outcomes of failed experiments #2 & #3:
2: clothes got dry, but uncomfortable until they got dry
3: wet sleeping bag, wet clothes

10. Get in Sleeping bag use Bring accessories: Get in
water (hot water bottle!)
snacks
headlamp
pee bottle (different to the touch)
Get in
Make sure bag doesn’t touch tent walls
Ventilate (unzip bag most of the way) once you’re warm-- Keep sleeping bag dry!
Fall asleep…..ZZzzzz

11. 1 am, you wake up cold and/or needing to pee
Sleeping bag use
1 am, you wake up cold and/or needing to pee
Your mission:
Eat!
Drink water!
Put on fleece layer
Do not delay getting up to pee!
Keep heat in- hood, draft collar, draw cords make a huge difference!
Use heat wisely!

12. Sleeping bag materials science: Down vs. Synthetic
packs much smaller (your pack might even be smaller than you are!)
2x lighter/warmer
lasts >>2x longer
cheaper in long run if cared for
useless when wet
Synthetic:
much smaller initial $$$ investment
less hassle with care & storage
less cruelty to animals
retains some warmth when wet

13. Sleeping bag care and feeding
Store Fully Lofted (storage sack)
Compress only for transport (stuff sack)
Compression sacks:
Let it dry! – during and after a trip
Washing your bag – down vs. synthetic

14. Sleeping bag liners Single-night trip: Silk liner
Keeps bag clean
Adds a couple degrees extra warmth
Multi-night, well below freezing: Vapor barrier liner
Prevents moisture buildup in bag (bag picks up several pounds of water, otherwise)
Adds up to 9°F (5°C) extra warmth
+ waterproof/breathable outer bag shell, protects down bag from moisture

15. Bivy sacs Typically for emergency use, most Winter School trips take 2
Basically a sturdy waterproof sac
Photo: Rolf Steinmann

16. Questions?