I noticed inflatable vests at REI advertized for emergency cold situations. They seem meant for short-term use only.

Better than nothing I suppose, and they are certainly compact. I am not sure but with a little modification they might double as a safety orange vest for hunting areas, and a safety vest to wear when dealing with roadway situations.

What so you think this technology is worth?

Do you have any link to this product? I couldn't find it at Rei...

Hypothesing wildly, I would think such a vest has certain benefits and drawbacks. The chief drawback is that anything inflatable will be air tight, i.e. a vapor barrier. Moisture from your sweat will be trapped underneath. Trapping moisture will result in condense at some point. This may be a slight nuisance, no problem or a big challenge, depending on circumstances and what else you're wearing.


The benefit would be obvious: A (supposedly) very compact, lightweight and warm west. The only competing technology would be down, but quality down is ridiculous expensive and don't work at all when wet.


As for the benefits of a west - to really protect your core you need to cover your head area as well. Since the west doesn't do it your clothing must do it. A hooded version would be more demanding to make, harder to use without rupture, cost more money and be heavier - and would be MUCH warmer.


I'd like to see when someone makes a super compact and lightweight inflatable emergency shelter... something like AMK bivy bag, but insulated. These guys may or may not be close, I don't know anything about their product except their web site:
Blizzard survival bag

Be Prepared also offers a Aerovest by SolaTec. Link also has their review on it.

Fill it with Argon.

Argon would displace Hot Air, the original filling. I am skeptical - the claims for this vest are likely to be grossly inflated, as it were.

I'll stick to down for really cold, dry conditions, and fleece and wool for wetter and more moderate situatiosn.

A thousand years ago when I was a little kid my Dad gave me an orange inflatable hood which was a survival item from Navy pilot's ejection seat kits.

Of course I tried it and yes indeed it made my head warm!

Inflatable insulation is a simple, functional, idea though it wouldn't be real durable and probably loses some efficiency due to air circulation within the chambers. Then again, it doesn't lose loft when wet.

I've used a partially inflated Thermarest lite seat mat as a chest protector inside a wind proof jacket in very cold windy environments and it works well when just standing around in the cold wind. If I was needing to sit down, I just inflate the lite seat a bit more then sit on it. Much more comfortable than sitting on wet grass, snow, cold rocks etc for a quick brew up. If was to begin hiking again I would just deflate it, roll it up and put it my jacket pocket. Taking of a Goretex jacket to put on a thermal jacket then putting back on the Goretex jacket can sometime be a pain in the neck especially if your brew stop lasts only 10-15 minutes.

The Thermarest lite seat is a great all round flexible bit of kit. Basically if you are having to rely on a SolaTec Aerovest for survival rather than already specifying good insulated clothing then basically you haven't prepared well enough for the weather conditions expected. A lightweight down or primaloft jacket would be much more preferable to the Aerovest.

http://www.sltrib.com/features/ci_13009009?source=rss

better than down?

Berghaus does a small range of Lithium Ion rechargeable power electrically heated jackets and gloves.

http://www.exo2.co.uk/berghaus_products.html#softcell

Combine it with a portable solar panel such as a Sunlinq 25+ Watt folding panel then solar radiation energy collected during the day could be stored and then used during the cold night time hours.

Now if they had a sleeping bag liner, which could measure the internal temperature of the bag and activate the heater pad automatically to regulate the temperature to stop that 4am waking up in the middle of the night cold effect...

Apparently REI online is out of this product; I saw a couple on the shelf at the local outlet.

http://www.rei.com/product/769403

The boots we wore during Artic training in Alaska were of a type that could be partially inflated to provide dead-airspace insulation. The "Mickey Mouse" boots were warm down, but you had to change your socks two or three times a day if you wanted dry feet - they held in all your sweat. I can see the same problem with the inflatable vest - warm but a massive moisture barrier with little to no venting. Wouldn't want to be wearing it and doing anything resembling manual labor.

Given how cheap, useful and common fleece is, why not just by a fleece vest?
(Or a fleece jacket, mitts and hat)

Somehow, I doubt it.

The whole point of insulation is to keep the warmth of your body near you. Air isn't the greatest of insulating mediums, since there's problems with radiant heat loss, right, and convection too if you talk about air moving within the garmet. Instead, by wearing clothes of different varieties, we keep the air around us "trapped" and thus slow the rate of heat lost to the environment. I can't envision how changing one gas (ie, air around our body) and wrapping it in another gas (in this case, argon) would help. I wonder if, instead, the jacket material is trapping the heat the same way a plastic bag would.

After all, think about a mountain top, say something in the Rockies. You'd think that being 10'000 feet up, you'd be 2 miles closer to the sun, and a bit warmer, right? Yeah, not happening.

I doubt it, too. Down and fleece work by trapping air so it can't move around as much, which reduces heat loss. Air free to circulate goes from the warm side, absorbs heat, moves to the cold side, and releases the heat to the other size. This is why vacuum bottles are such a great thing - no air means no convection or conduction.

I believe argon has about 2/3 the heat capacity of dry air, so it would be a little better, in the same way steel doesn't conduct heat as well as copper.

All that said, it's a pocket sized thing where a fleece or down vest is not. I knew I saw it somewhere...here's a link for sale, and a review:

http://www.bepreparedtosurvive.com/ProtectionProducts.htm

I have no connection to the site, but have read from someone on here that it's reputable.

I believe this product is focusing on storage space, being small enough so that you would have it in a smaller kit you would actually carry. The combo you suggest would be quite a bit bulkier in your kit. This vest is not the best item to have for hypothermia, but I believe it does meet it's objective. A polypro balaklava with gore-tex hood would be a good addition as would many other things. With all the kits you may envision, you need to choose between bulk, utility and odds of needing that category of gear. This fills a particular nitch, but may not be an item you choose to go with.

Here's another write-up:

http://207.210.105.72/~halcon21/forum/index.php?topic=567.0

You need to make tiny pockets, not just a giant air bubble that allows the air to circulate freely. Like a thermarest ground sheet - it has lots of pores that are filled with air.

Dead air isolates. Allow the air to move and the density differences between warm and cold air will set up a circulation which carries heat away from you.

The US military "Mickey Mouse" boots with the air valve on the side are designed to never open the valve unless in an aircraft. Primarily for a change in pressure. It is recommended that you so not open the valve and certainly do not inflate the boot. The reason is by blowing breath into the boot insulation you introduce moisture which freezes and compromises the insulation. This info comes from the tag on the boot and from the Cold Weather Operations manual. Just a FYI.
I would expect the same results using the air vest, in the right cold conditions you could have a vest of air and ice crystals.