Winter Awareness
Sleeping Systems
Sleeping Systems
• Course Objectives
– Explain:
• The need for insulation above as well as below you
• The ways body heat is lost and methods to
preserve it
• The ways and means of sleeping warm during cold
and wet weather
• How to “winterize” your existing sleeping bag
The Million Dollar Question?
If you knew you were going on a camping
trip and the weather was going to be
below freezing, would you rather take 6
inches of wool blankets or a 6 inch down
sleeping bag?
Ways Body Heat is Lost
1. Radiation
2. Conduction
3. Evaporation
4. Convection
5. Respiration
Radiation
• Cause:
– The heat the body sends or radiates outward
• Prevention:
– Dress properly for sleeping. Cover the head?
Conduction
• Cause:
– Heat will always travel to a cooler surface.
• Prevention:
– Insulate your body from cold objects, like the
ground.
Evaporation
• Cause:
– Body heat turning bodily liquids to vapor
• Prevention:
– Reduce physical activity to reduce sweating
Convection
• Cause:
– Air movement. Warm air is
replaced by cold air.
• Prevention:
– Dead air space.
Respiration
• Cause:
– Breathing out warm air and taking in the cold
air.
• Prevention:
– Avoid heavy exercise before bed so you won’t
be breathing heavily.
Sleeping System
Ground Cloth
– Purpose
• Keeps ground moisture out
• Protects tent and sleeping bag – keeps clean
– Qualifications
• Large enough to cover sleeping area, but not too
large
• Thick enough to prevent punctures and rips
Bottom Insulation
• Purpose
– Your body compresses the sleeping bag and
loses all the loft below you.
– Prevents conduction of heat
Bottom Insulation (cont.)
• Good materials to use alone
– Any closed-cell foam pad
• Doesn’t soak up water
• Doesn’t let air pass through it and prevents
convection
– Therm-a-Rest
• Waterproof
• Prevents heat loss through conduction, convection
and radiation below you.
Bottom Insulation (cont.)
• Bad materials to use alone (but may be
used in combination of two or more).
– Cot: lets air circulate beneath you
– Open cell foam pads
– Newspaper (at least 1 inch thick)
• Bad materials to use anytime
– Air mattress: your body doesn’t have enough
energy to heat up the air inside of it
What to look for in a sleeping bag
• Do you need a 4 season bag?
– How often do you go winter camping?
Sleeping Bags
• Should be rated to temperatures below
what you expect.
– If nighttime temp can drop to -15o, then bag
should be rated to -30o
• Variety of fills for sleeping bags:
– Down
– Microloft
– Polarguard
- Primalof
- Qualofill
- etc.
Material Types
Qualities
Cotton
Down
Wool
Polar-guard
Hilofill
Fiberfill
Thin-sulate
Wt per
insulative
value
High
Low
High
Moderate
Moderate
High
Very Low
Thickness
per ins value
Very
Thick
Thick
Thin
Moderate
Moderate
Moderate
to thick
Thin
Warmth
when wet
Very poor
Poor
Good
Good
Good
Good
Good
Length of
time to dry
Long
Very
Long
Very
short
Short
Short
Moderate
Very Short
Compress-ab
ility
Low
Great
Low
Moderate
Moderate
Moderate
Low
BreathAbility
Fair
Fair
Moderate
Moderate
Moderate
Moderate
Good
Durability
Poor
Poor
Good
Moderate
Moderate
Moderate
Good
Mach.
Wash
Dry
Clean
Dry clean
Mach.
Wash
Mach.
Wash
Mach.
Wash
Mach. Wash
Low
Very
High
High
Moderate
Moderate
Fairly Low
Moderate
Nearly
worth-less
Poor if
wet
Great
Good
Good
Fair
Great
Care required
Cost
Overall value
for cold weather
camping
Fit: 3 shapes
1.
Rectangular
2.
Tapered
3.
Mummy
Bag Liner ?
We recommend a mummy bag.
Big Bag
+ Little Scout
Bad Times
Loft:
• How easily does it compress?
• Does it bounce back?
Shell:
• It should be made of fine weave or rip-stop
nylon.
• The 2 pieces should be cut differently for a
smooth fit.
– Materials
– Pick one that best suits your needs
Zipper
• Should be made of plastic.
– Doesn’t conduct heat as fast as metal.
• It should run from top to almost bottom
• Should have 2 sliders
– Can be opened at the top and the bottom for
ventilation
Draft Tubes & Hoods
• Draft tubes block air coming in through the
zipper.
– Should be fully insulated and extend beyond
the zipper
• Hoods should be fully insulated and able
to close around your head, leaving mouth
and nose open to the air.
Workmanship
• Stitching should be straight with 8 to 10
stitches per inch
– Should have double-stitching at points of
stress (such as the zipper seam and the
hood)
Caring for your Sleeping Bag
1. Unpack at least 1 hour before using.
2. Keep your sleeping bag as dry as
possible
3. Air out if possible to dry out any hidden
moisture
4. Don’t store compressed or in a tight stuff
sack between camping trips (causes loss
of loft)
Tents & Dress
• Tents
– Why are they important?
• To create a blanket of dead air space around you
• Dress
– Only enough clothes to keep you warm, but
not enough to make you sweat
– All clothes should be clean and dry, not the
ones you’ve been wearing all day as they
have hidden moisture from perspiration.
Winterizing your Summer Bag
– Materials: sleeping bag & 2 or more blankets
– Open your bag up all the way
– Lay blanket so it covers ½ of the bag
(lengthwise)
– Lay second blanket so it covers entire
sleeping bag
– Lay extra blankets in the same manner
– Lay down where blankets overlap
– Fold blankets over you one at a time
alternating sides
– Zip up your sleeping bag
Scout Burrito
Lay Here
2nd Blanket
1st Blanket
You
Sleeping Bag
Blankets
Tips
1.
2.
3.
4.
5.
Don’t sleep in the bottom of the bag.
Keep some high energy food nearby.
Go to the bathroom before bed.
Don’t dry wet clothes in your bag.
Put tomorrow’s clothes in or under your
bag.
6. Fluff up your bag to increase loft.
7. Keep all of your sleeping gear dry.
Which is Better?
• 6 inch thick Down sleeping bag?
• 6 inches of Wool blankets?
Any Questions?
?
Thank you