Sleeping Bags

I see FA website lists it at 1.6kg, and CUM at 1.4kg.

I checked my Ice Breaker for you on two scales, both 1.6 kg, with the stuff bag, but excluding the compression top and straps which I never use.

tonymarshall wrote: I checked my Ice Breaker for you on two scales, both 1.6 kg, with the stuff bag, but excluding the compression top and straps which I never use.

Thanks Tony, much appreciated.

For a cooler weather bag, aside from the ability to open the bag fully, are there any benefits to a full zip, as opposed to 1/2 or 3/4?

Thanks
Papa D

A zip is a "cold spot" - the loft of the bag is what generates the warmth. At the zips, the bag is compressed, both the zip itself, and the bits close to the zip. I believe that is why lots of the warmer bags use shorter zips.

I still need to have an opportunity to test my quarter zip on my Hyperlamina Torch, so I don't have actual data to make a comparison.

This is why a hypothermic person cannot necessarily come right on their own

This is also why another person would dress down and get into a sleeping bag with the hypothermic patient in severe cases.
Suggestion to the girl hikers, don't get hypothermic unless you really want to get up close and personal with somebody in your group. (I suppose when you get to that point you won't care, right?)

@Intrepid: Indeed - a case of not checking my wording before posting

When I had hypothermia in 2012, John Pickup made me jump into my sleeping bag and drink something hot, and when Hobbit had hypothermia on my most recent GT, I did the same. I disagree that the warmth retained by a sleeping bag wouldn't work - simply because hypothermia is body temperature of something like 32 degrees, but when you have hypothermia in the Berg, it is usually because your clothes are wet and there is a wind. So if you get the wet clothes off and get into a sleeping bag, you warm up quite quickly.

I imagine this isn't true if you have hypothermia secondary to altitude sickness or hypoglycemia though. I.e. it makes a difference if the cause is internal vs external.

Use of each others body warmth would not be my first line of attack though - a hot cup of tea/water/soup works very well as it warms the person up from the inside (just be careful of burning them). That part of the Everest movie where they put the frozen hands in boiling water - I am 90% sure that is not a good idea as I have often read that you should never externally heat up a person's extremities when they have hypothermia as it may cause secondary hypothermic shock (i.e. cold blood being forced to the heart). If I got stuck on top on a day hike and had to bivy without any warm gear or sleeping bag, then you most certainly would have to use each others heat though.

Hypothermia is defined as a drop in core temperature to less than 35C, and can occur even at warmer temperatures given the right circumstances. Half of heat loss in colder temperatures is via radiation from the skin.

Dehydration and calorie depletion predispose an individual to hypothermia.

Be aware of the Swiss Mountain Medicine field (clinical) definitions for Hypothermia:

Hypothermia I (Mild): alert, uncontrolled shivering: 35 – 32C

Shivering is most effective with removal from the cold. Limited exercise may help. Eat and drink.

Hypothermia II (Moderate): altered mentation, shivering stops: 32 – 28C

At this point the person must be actively warmed because they are unable to warm themselves.

Hypothermia III (Severe): unconscious: 28 – 24C

Handle carefully as the heart becomes progressively more irritable below 32C

Hypothermia IV: Not breathing: <24C

Shivering is an effective warming mechanism initially caused by skin temperature changes rather than changes in core temperature. Core temperature drop is caused by cold blood returning from limbs during rapid rewarming and can complicate rewarming efforts. Slower rewarming may reduce this complication.

awls.org/wilderness-medicine-case-studies/hypothermia-fundamentals-and-treatment/


1. Symptoms of hypothermia in adults and children include:
Confusion, memory loss, or slurred speech
Drop in body temperature below 95 Farenheit
Exhaustion or drowsiness
Loss of consciousness
Numb hands or feet
Shallow breathing
Shivering
In infants, symptoms include:

2. Restore Warmth Slowly
Get the person indoors.
Remove wet clothing and dry the person off, if needed.
Warm the person's trunk first, not hands and feet. Warming extremities first can cause shock.
Warm the person by wrapping him or her in blankets or putting dry clothing on the person.
Do not immerse the person in warm water. Rapid warming can cause heart arrhythmia.
If using hot water bottles or chemical hot packs, wrap them in cloth; don't apply them directly to the skin.

3. Begin CPR, if Necessary, While Warming Person
If the person is not breathing normally:

For a child, start CPR for children.
For an adult, start adult CPR.

Continue CPR until the person begins breathing or emergency help arrives.

4. Give Warm Fluids
Give the person a warm drink, if conscious. Avoid caffeine or alcohol.

5. Keep Body Temperature Up
Once the body temperature begins to rise, keep the person dry and wrapped in a warm blanket. Wrap the person's head and neck, as well.

www.webmd.com/first-aid/hypothermia-treatment

My current Winter sleeping bag ( Cape Storm Firefly ( down) goes down to – 7 degrees and weighs in at about 1.2kg) has given me many years of faithful service but as my mission these days is to cut down on weight, I have been exploring my options. Nothing local can meet the criteria – ie, weight/warmth/packdown space, so I have taken the plunge and ordered a bag from a Company in the States – ZPacks. My daughter who lives in New York was able to bring it out for me, so I saved a lot in import duties and vat – nonetheless it has been an expensive exercise at USD 420.00. This was in November last year and the exchange rate now is even worse. The bag is made to measure and I have chosen a slightly longer length and width plus a two way zip and baffle. This bag weighs in at 628grams. A hiking friend of mine has one as well and she is impressed – her only comments were that one does need a slightly longer length as there is no cowl. I am dying to try it out but will have to wait for the Berg winter to arrive! I will give a report back on its performance once I test it.

Here is the link to the website

www.zpacks.com/quilts/sleepingbag.shtml