i was cold…

What was on your head?

i was wearing a stocking cap the entire time and i forgot that i had on a shell jacket too.

<— that hat and that jacket to be exact

For a windy 30F evening you were drastically under dressed for sitting around. While you were exercising heavily you were producing a lot of heat and could get by lightly clothed. Once you sat down you were producing less heat than you were losing.

Take a look at Richard Nisley's article:
http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=9378

Using his chart, when sitting and talking at 30F you need insulation with an lcl clo of about 3.50. You'd need at least a Pata. R1 hoodie plus a Polarguard Micropuff pullover and vest. Probably you'd need an additional layer over all that.

It was windy so that made it worse.

For those conditions I'd think you had three choices:
carry a down parka,
get into your sleeping bag while eating,
or, as you did, use a fire to keep warm.

Having been there, done that, I agree with Walter 100%. A nice warm puffy parka with hood was needed. It might also help to have more leg insulation while sitting around (base layer bottoms would probably do it, under your hiking pants and with rain or wind pants on top).

Low 30's with wind (windchill in 20's) would require more windblocking/insulation. A vest won't cut it for me at those temps. We had one evening like this, but had no shelter in where we were cooking our meals. Everyone retreated to their tents/sleeping bags very early.

To be shivering that quickly, I wonder if it's a combination of:

1. your inner layer was sufficiently soaked by your sweat — even if you didn't feel the full extent
2. your additional layers were inadequate for resting @ low 30's
3. your body was already too tired out to reheat all over again

I think collecting firewood while dressed inadequately delayed the cold — but only tired out your body even more — so when it did feel the cold, it came fast and furious?

When you arrived at destination, I wonder if you could have avoided the shivering by:

1. changing out your wool shirt — or at least add a heavier insulation (if you had one)
2. snack on some trail food, etc. and give your body a rest (or snack and gather firewood if it was getting dark already)

here is exactly what i was wearing:

BPL headsweats beanie cap
smartwool merino ss med weight shirt (worn all day)
smartwool merino ls med weight shirt (worn all day)
rei polyester ls shirt
rei primaloft vest
marmot precip jacket with hood

rei all season polartec gloves

rei sahara pants
exoffico boxer briefs

smartwool ankle high socks

oboz yellowstone II boots

i will add that i have dropped 15 pounds in the past 2.5 months and being cold like this is a recent experience.

Yes, the getting cold quickly could be due to "flash off" of even mild sweating that you are not aware of or not feeling sweaty. Ryan Jordan has a good article on thermoregulation.

http://www.backpackinglight.com/cgi-bin/backpackinglight/00184

"Take a look at Richard Nisley's article:
http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=9378&quot;

That article has got to be one of the greatest posts evah. It really laid out the basic scientific principles of matching clo to activity. After (re)reading it many times, it finally struck home that we are essentially only doing three things:
1. hiking
2. sitting
3. sleeping

Each require their own clo configuration, ranging from least to most. Add in temp(s), rain, wind & dew point and the problem becomes one of mixing & matching for all possible combinations.

That's why you need limited clo while moving, but a lot of loft while sitting, and even more when sleeping. Hence, the classic (progressive) combo of capilene, polartec, windshirt, shell, vest/parka, bag/quilt and bivy/tarp/tent.

Sounds just like a lot of thin layers and not much insulation. Agree with Walter. You were simply under insulated while stopped and not moving. You should have a parka that you can put on over all other layers. You don't want to be changing out layers in those conditions when windy and stopping/starting. The other benefit is if some of your layers are a little damp, having a parka that breathes can help your body heat push that moisture out and dry you out quicker. Something like the GoLite Bitterroot which uses Pertex Quantum shell fabric.

http://www.golite.com/Ms-Bitterroot-850-Fill-Down-Jacket-P46646.aspx

To me it sounds like dehydration.

While I certainly don't want to underestimate the importance of adequate hydration–just as important to prevent hypothermia as to prevent hyperthermia–this case appears to be primarily insufficient insulation for sitting around camp.

It is all too easy not to drink sufficient liquids in cold weather, though!

It sounds like a lot of sitting around underdressed in cold windy conditions. My SOP in winter is to start heating water for instant soup as soon as we set up camp. I've never used an AT Shelter- but it sounds colder than a tent if one side is open. If you're cold, put on more clothes, drink hot beverages, eat food, and get in the sleeping bag. Either that or practice your dance steps.

I usually consume at least a liter of hot soup, cocoa, and/or tea between arriving in camp and bedtime. It's pleasant, warming, and beats back dehydration.

While dehydration and lack of food may have played a factor, with only a vest you're going to be COLD at those temperatures. Especially if you aren't totally dry.

Soup and tea. Keep it coming. Go to bed at 6:30 after a big fat bomb of a meal. And shelters are never as warm as you hope they are.

Anytime you have been working hard, when you stop you will cool off pretty quickly. But more than that, I find that my metabolism goes below the usual baseline. By that I mean that if I wear what I would normally need in terms of insulation to keep warm at a given temperature just sitting around, I'll need more than that for a while if I am recovering from exertion. And the effect is even worse If I haven't been eating enough.
So, if this is your experience you may need to up your insulation somewhat to handle it. How much experience do you have with sitting still in these temperatures with this combination of clothing? Finding out what your individual clothing needs are is a trail and error process, and while certain rules apply – like keeping your head, hands and feet well insulated, keeping your insulation dry and so on – no one can tell you which precise combination of clothing will keep you warm in what conditions, due to personal variations. You have to find it out for yourself.

I find that It's a fine line to walk when adding insulation after exertion -it's easy to put it on too slow or too fast. Too slow and I experience what you did. Too fast and I get sweaty and that starts a see-saw of hot and cold.

1. insufficient insulation … i personally like to bring more insulation than needed for camp/belays … with UL gear weight aint a huge issue IMO these days … id want something with 4+oz of 800+ down fill for 30F minimum, or synth equivalent … put it on right away anytime you stop for more than 5 min … preserve that body heat

2. insufficient food … im not quite sure of yr menu, but packing some cheese or sausages (something with fat) will warm you up pretty well … freeze dried aint the best IMO for keeping warm … it aint UL, but bring some fatty foods

3. weight drop … once you lose a decent amount of fat, youll require more insulation … i noticed this last year when i dropped ~15 lbs

solution … bigger poofay and fatty foods …

what would be the synth equivalent for you?

100g/sqm synthetic fill or more?

I suppose everything lighter that the 100g fill might be to cold, right?

at minimum …

what i will do and in fact what i used for climbing today was use a down vest under a synth puffy for belays around freezing

itll solve the moisture issues … and you can use the synth puffy for moving slow or quick stops, only exposing yr down puffy in camp … and is likely a tad lighter than a pure synth puffy for the same insulative value

using my 50$ EB FA downlight vest and 19$ old navy synth poofay right now …

1) Your base layer(s) were probably wetter than you thought. Get out of it asap. Wool holds a Lot of water. Feels wonderful, but holds a lot of water while feeling "warm".

2) Need a puffy layer. Down jacket etc as everyone else said. Another layer on your legs also.

3) A bit of sugar and fat right when you stopped wouldn't have hurt. I prefer washing dishes when its warmer out rather than when its colder out and warm food helps the change from exertion to stopping.

some excellent comments, thank you.

in retrospect i believe that several factors came into play given that i did warm up after i had eaten. my wool shirts were wet, when i removed them at bedtime they the back area was damp. my energy stores weren't enough to stoke the furnace to warm me up right after hiking for 6 hours. i should have eaten something right then for sure. i think i mindlessly stayed in the wind when i got to the shelter while waiting for my buddy. i should moved into the protection from the wind and swapped my shirts, donned my layers, and had a bit to eat.

if the temps with the wind chill are going to be below 40F, i'm bringing the puffy jacket. warmth and comfort trump bulk and an extra 12 ounces of weight. i would have been miserable a second night for sure.