Hypothermia question

[naisme]

I think I was close to it last night. I started feeling a bonk on the commute home in sub-zero temps. By the time I got home I was not shivering but I wasn't starting to warm up either, so I jumped in the shower, it took a long time, or seemed to be a long time, to warm up. My heat is controled by the landlord, so there's no turning it up.

But that feeling of not being able to warm up bothered me. I know in another thread we discussed the body's thermostat, and the cold might affect it. I also know from reading and winter survival classes, that you don't want to do anything in this sort of cold alone, because solo, you may not see the signs of hypothermia, before it is too late. That's a scary proposition.

What are the cures/preventions that you have tried successfully. I'd like to know, cause this ride, even as cold as it was, has me thinking the Iditerod would be a fun bike race to train all summer for.

[Ebbtide]

Strange question, IMO. Just stay out of the cold.

http://www.princeton.edu/~oa/safety/hypocold.pdf

Hypothermia is something you can't treat yourself (with any degree of success). You do want to avoid it at all cost, if that means you say off the bike, then stay off the bike. Hypothermia can act quickly and is fatal.

Other than that, dress warm, eat, keep moving, and stay hydrated.

Hope this helps.

[bac]

Sorry Naisme, I don't have any answers or comments for you, but this "may" clear things up. It's more about swimming than biking, but you may be able to draw some common ground. Anywho:

Look Out for Hypothermia (http://www.threebrain.com/songs/hypo.html)

[Jean Beetham Smith]

Naisme, here is Boston area we rarely get as cold as you do. The coldest I have ridden in was -3F/-19C, but anytime it is below 15 I make sure that certain ER items are in my trunk or pockets: heavy wool mittens with leather chopper overmitts, an extra dry fleece or jersey, a dry balaclava, 2 sets of "Grabber Mycoal" or similar hand and toe warmers, and my ski goggles. If it is below 5F, I wear the goggles. Somedays my hands get much colder than others even though I've dressed the same. I've found that stopping and changing to the mitts usually fixes the problem. When it drops below 10F my first priority is getting there safely, not setting any speed records. I drop back to safely in my aerobic limits to cut down on heat loss through increased breathing rate, and to be sure I don't sweat too much. So far, I've never had to break out the handwarmers or toe warmers on my 10 miles each way commute. If you ever think you are getting in trouble, get to shelter to warm up. Make a habit of knowing where the donut shops and convenience stores are. Don't hesitate to call 911 if you are in trouble. I always carry my cell phone inside my jacket so I can be sure it will work if I need it. Since I ride through a semi-rural area, I make a habit of knowing a few houses where the people always wave to me. In a pinch, I figure they would let me wait there until someone picked me up. Oh, and if you have a tub, a hot bath will warm you faster than a shower.

[DanFromDetroit]

I carry a backpack most all the time, I am either biking, running, or walking most everywhere. Since I am in an urban area my trips are usually short with frequent stops, my choice of "extras" will likely be different than yours.

I carry extra:

gloves (a small knit pair) that can be used either as liners or just plain gloves.
head covering. usually a fleece headband.
small led flashlight
large silk scarf, that can be folded small. This can wrap around your neck or head. You would be suprised how warm these can be
Cotton bandanna.
Victorinox "Soldier" pocket knife
a couple of plastic grocery bags. These are good for keeping things dry but could be used to keep feet warm (inside boots) in a pinch
Lip Balm. Great for chapped lips, but can be used on nose and cheeks in extreme cold and wind.
cell phone
bus pass
loose change
20oz water
If I know I am going out for a long time, I'll carry a small snack and a dry shirt.

[Coda1]

A few times when I was cold and wet I was unable to get my little finger to move on its own up against my other fingers when my fingers were not bent. Even after warming my hands over a fire I still could not do it. After the rest of my body warmed up I could. I think it was the beginning of hypothermia. I have never heard of anyone else having this happen though. If you are dressed warm enough and stay dry you should not have a problem.

[iceratt]

With enough layers, one should be able to stay warm while biking 10 miles, at -10F. As ehenz says, it is important to have hydration and fuel( nurishment). I disagree with him that you should stay off the bike when its this cold, if you regulate your body temperature by working hard enough to produce the required heat, and add or subtract layers as needed to prevent chills and saturation from sweat.

I recently read a post on another web site, written by a man who was racing 100 miles on foot, in winter, in the middle of Alaska. He had support, but had to stay on the pavement during the run. with that much work, he had to eat, drink, adjust clothing, and urinate several times during the gruling experience. Just the fact that one can do that, is testiment to the ability to ride a few miles in our comparitively balmy clime. So of course you can do it safely, if you're careful!

Protecting oneself from frostbite, thats another matter. Now we're talking about my bane!

[jeff williams]

A thermos with hot water, honey and lemon, drink some before and during.
I find its faster and easier to warm up from the inside using circulation than the exterior to internal-though go easy-if you have dropped real low, have a hot bath AND hot liquids after a very cold bike ride-could affect your heart\shock. My non-medically credited advice.

[Pat]

Hypothermia can be bad news. I did a tour in Colorado. We started at Silverton. The first day was short. Just over Red Mountain Pass at 10600' and down to Ouray (a really long descent).

Well anyway, I was climbing along and about halfway up it started to rain and thunder and come down in sheets. So I got on my trusty rain suit and I had a long sleeved jersey and tights. The rain slackened as I approached the top, merely a light shower. But I looked up above the pass and about 500' up it was snowing and sticking. So it was good and cold. Our van was at the top of the pass and I knew the 6 miles down to Ouray was going to be REALLY cold. No pedalling and wet. So I decided to ride down in the van. Part way down, a landslide of mud came across the road and stopped. It was pretty neat. One minute it was like a river of mud and then it just stopped and solidified instantly. We got around it (there was a wide wide shoulder here because I guess that happens a bunch.

When we got down to Ouray, I found my roomate Robert at the motel. His lips were blue and he could not talk. Hypothermia. So I took him into our room. I ran a hot shower and checked the water with my arm to be sure it wasn't too hot. Bob was too cold to notice anything and I didn't want to burn him. I undressed him (his hands were too cold to undo the buttons). I shoved him into the shower. About 5 minutes of that and he could talk. We went across the street and poured 2 hot chocolates into him. That helped some more. There was a public hot spring in town and we went down and Bob got into the hot pool and after 30 minutes he was as good as new.

I don't know how he got down off that pass without going over the side. Guess he used all of his remaining awareness on just keeping on the road.

A big problem with hypothermia is it affects your judgement and people often do not even realize that it is happening until they are too far gone to do anything about it.

[iceratt]

What Pat said about hypothermia is mostly correct. The victim was brought back to health, but there was some risk in treating him without professional emergency medical assistance. The shower was a mistake, and 911 should have been called. Even after he looked alright, he should have been evaluated, because he went beyond the definition of mild hypothermia.

A hypothermic victim should be gotten out of the cold, wet, windy condition as quickly as possible. This might mean stripping him and covering with dry layers.
His body should be kept horizontal, to prevent shock and increase blood flow to the brain. The limbs should be moved as little as possible and not heated, because this can cause colder blood in the extremities to be pumped to the core. Warm the core with dirrect body heat ,prefferably from another person. Be careful with hot packs, because the very slow circulation makes it much easier for the victim to be burned. Only give warm fluids to someone who is fully alert, and is at no risk of choking on it.

[late]

Hi,
you could also take this subject up with backpackers, esp winter climbers, x/c skiers, ice climbers, that sort of thing. Cyclists get a double whammy. The intense exercise can cause sweating, the wind chill can suck heat out of you like a vampire. Screws your judgement all to hell. Prevention is the only real solution.
Dress in lyers, unzip when you get hot, rezip before you get cool. The palms of your hands and the bottoms of your feet have this weird thing that if they get cold it can trigger the extreme reaction to cold. That is very bad news, as that deprives things like your brain of what it needs. Oh, eating is another thing to do. Eat like a eskimo.
You want fat flavored with a dash of this and a soupcon of that all drowned in more fat. Hey, you asked. All clothes do is slow heat loss. Burning calories generates heat, and nothing does it better than fat.From your descrption, it looks like you simply didn't eat enough. If you're going to play games like this get an electric blanket. When you get home chilled to the bone, have some soup, crawl under the blanket, and crank that sucker up to the point where it will melt lead. This is not good of you're genuinely hypothermic (too fast). Works wonders if you're just colder than a witches teat.
I have mixed feelings about hot baths and showers. If the water stays good and hot, it's prob ok.

[iceratt]

Hi,

I have mixed feelings about hot baths and showers. If the water stays good and hot, it's prob ok.

What naisme described is not severe hypothermia, by a long shot. Pat's description, on the other hand is of a man at some risk of dying. There's no 'prob' about it, as if this were a matter that could be resolved by debate. The heart can have arrythmias and the blood chemistry can become altered in ugly ways. By impropperly rewarming a victim, people have died needlessly. I have some medical knowledge, and did a little research prior to writing my post.

I think that we are all better off if we know about hypothermia, as it could affect extreem weather cyclists. I'd be happy to write more, as it pertains to our community, if there is an interest.

Unless you really know what you're talking about, I think its a disservice to give advice on a life threatening condition, such as this, late. Sorry, if I sound harsh.

[late]

Hi,
not a prob. If you're coherent enough to deal with the situation, you prob don't have severe hypothermia. Been there done that.

[Zin]

<snip> I'd be happy to write more, as it pertains to our community, if there is an interest.

Hey iceratt! Please go ahead and write more. This is one of those topics that a guy in the north country can't know enough about.

Thanks
Bob

[naisme]

I really appreciate the knowledge shared on the subject, and agree that more could be written on it. I know that I was in some trouble when I pulled off my sweater and windshirt and wasn't sweating. I hadn't thought that breathing would cool me down.
A couple years ago I had an incident on a commute to work that really scared me. I had ridden 10 miles, and came to my "rest" stop before going on to work, another 4-5 miles. It was winter, and cold, and I was thirsty so I drank from my freezing water bottles. As I took off to continue, I began to shake/shiver, and did so the whole rest of the ride. This experience was the one that taught me about not wearing cotton, and get a different wind shirt, I was wearing a pullover rain coat, that didn't breathe, it trapped moisture, my clothing got wet, when I stopped it got cold, add the cold liquid in my stomach, and I was a mess. I vowed to not let that happen again. Fortunately I lived to tell about it, and learn from it.

[iceratt]

OK folks, here is a little more info on hypothermia. I think that from my prior post, it might have seemed that the 'victims' were in a bit more danger than they were. Hypothermia is a potentially life threatening condition, but our 'case studies' were of individuals in mild hypothermia, which has the greatest risk from accidental trauma secondary to clumsiness and dissorientation, and impaired judgement( the individual might not know to get in from the cold, nor want to).
In mild hypothermia a warm bath is probably ok, as is a shower with assistance, if the individual has impaired coordination.

Some basic information:

Core body temperatures:
mild hypothermia 34-35C
moderate hypothermia 30-34C
severe hypothermia <30C

What to expect phsysiolgicaly at various core teperatures:
37 Normal
36 Increased metabolic rate( quicker breathing and heart rate and the like)
35 Maximum shivering seen and impaired judgement
33 Severe clouding of consciousness( this would be when an individual appears very drunk or stuporous)
32 Most shivering stops, pupils dilate
31 Blood preasure may not be obtainable
28-30 Severe slowing of pulse and respirations, muscle rigidity, severe heart arrythmias
27 person appears dead
16.6 Lowest known body temperature of a revived individual

Preventitive steps to avoid hypothermia include:
Being prepared for climate changes by having plenty of layers and at least one to keep you dry.
Carying a cel phone
Riding with a partner, who checks in with you occasionally
Eating and drinking to replace what you are using up
Avoiding alcohol( I'll say more about htis later).
Don't be a stupid, after midnight, winter commuter in Minneapolis- oh uh, thats me. Just be careful if you do this kind of stuff!

Treatment of hypothermia in the field:
Get the victim out of the cold, wind ,snow, or rain. Make a shelter, if you have to.
Conserve share, create warmth- fire, warm liquids, warm packs, body to body, ect
Make sure victim is in dry layers or bundled,stripped to underwear with rescuer.
Use care in moving victim, watch for trauma that he might not notice.
Send someone for help or call 911, if you're issolated.
Don't give liqiuds to a person who is not fully alert.
Don't try to rewarm a person who has been moderate to severe hypothermic, for a long time. Use only passive insulation, such as blankets, to avoid severe heart and blood chemistry problems. Put them in a horizontal position. Avoid moving and pumping their muscles as much as possible.

Alcohol use is bad for several reasons in a person who is cold. It clouds a persons judgement. It causes diuresis( makes you urinate more than the water volume than is consumed) and dehydration, which decrease ones ability to regulate heat and impairs judgement further. Alcohol also increases vasodilation, bringing more blood close to the skin, which increases heat loss.

Much of the information I have here, I took from Dr Andrew Weinberg, of Harvard University. I hope he's ok with my paraphasing and plagarism. I am not a doctor myself, just a country psych nurse. I post this in the hope that it is accurate, useful, and allows others to make better decisions than they would without it. I have hit on what I thought were the most important points. I invite others, who might know more, to add their two bits.

If the Forum Gods think its a good idea, maybe this should be posted where others, besides winter cyclists will see it.

[naisme]

Ice, good work...

[leconkie]

Very interesting. It's this kind of stuff we need a bike forum for. Thanks iceratt. I remember a friend who had a buddy in the army go into shock thru heat exhaustion on a training run in Asia (don't know where). Anyway as usual with the army, they didn't take any notice of his pain until he collapsed and was fluttering around consciousness at which point they got a bit worried. So they picked him up, carried him back to camp and......
threw him in a bath of icewater. He ****ing died of ****ing shock right there and then.
Anyone know the signs of heat exhaustion or dangerous overheating and how to deal with it? Do you get impaired judgement like with hypothermia or anything?
Cheers

[iceratt]

Thanks leconkie. I enjoyed researching the material that I posted. At the time, it would never have occured to me to do a similar post on hyperthermia, as I forgot what being warm was like in February in Minnesota. After I take care of celebrating my wife's birthday in a few days, I might be able to write about this risk, which is more likely to us northern hemispherians.

[Balance]

yeah, hypothermia. One thing to look out for is lethargy and irritableness. If you're in a cold environment and you're all like, "well, who cares anyway, it's not that bad. I just don't want to stop/go inside. Grrr, why are people so stupid?" That's a bad sign. If you're aware of the signs of hypothermia you're more likely to figure it out. Generally you won't realize you have hypothermia, but you can realize that you have the signs and put 2 and 2 together. A few weeks ago I was hitchiking through new brunswick and it was really cold at night. I was having really bad luck and i didn't sleep for four days, didn't eat much either. I wouldn't sleep at night because it was too cold for the gear I had, and just had to keep walking all night to stay warm. But sometimes I would get too sleepy and too cold and that lethargy would kick in. Lay down on the ground, without sleep pad, without sleeping bag, just with my poncho over me. "Yeah, just catch my breath. Just close my eyes for a minute." One time my body woke up from the cold, but I wasn't shivering _anymore_. "Oh, it doesn't matter, it's not really that cold, maybe I'm just dreaming...dang I hate new brunswick...dang, irritable, lethargic, not shivering, I KNOW it's cold... whoops!" At this point if you're alone and you're moderately hypothermic you need to really concentrate to get yourself out of it. What I did was flex my arms and legs to generate heat until my body was warm enough to roll over onto my stomach. Then I slowly did easy push ups to generate more heat. Then I pushed myself up, put my poncho on and began walking in circles,then doing little jumps. You need to very slowly rewarm yourself and fight the desire to just not care. Eventually I walked until I got to a truck stop with a 24hr diner, went inside, and didn't even think about drinking coffee until the room temperature warmed me up -over half an hour. I just told the waitress that I had to wait before drinking warm liquids. Another time with hypothermia I was winter camping with a friend and she got damp from building the quinzi (snow cave) and she was getting the lethargy and irritableness and irrationality. We aborted the camping and headed home, warming up with the movement. It's really hard to rewarm unless you get indoors. Too risky.

[Ronocerous]

Maybe make a note of the factors that led to this, Naisme. Temp, windchill, clothing, MPH, etc and try to avoid that combo again. I know that I commute alone so noone is going to see the signs. I know there are times in -20C when I can stop to warm my hands up. Other times, like tonight (only -7C with a slight windchill) when I feel I have to cut my errands short, which I did, and get home. It's just a feeling - a cold toe or finger is one thing, but feeling cold at the core coupled with a wet from sweat and I know its time for me to get off the road and into some shelter.

In general I try to push myself a little. I try to do more and reach new goals and stuff, even while commuting. But all that stops when winter comes. Like one poster said, it's about arriving safely. You know all this, of course. You're an experienced winter rider. That's what makes this episode so frightening to us; well, me anyway. So, any more thoughts you might have on the circumstances of your ride might be helpful.

[CommuterKat]

Thank-You for posting this here. I am commuting for my first winter this year, and am already learning the hard way about how to dress, how hard to push, and the effects of wet clothing. Thankfully it isn't getting really cold here yet. I think the coldest I have ridden in is high 20's to low 30's F.
Does sipping hot liquids really help? And if so, where can I find a thermos that fits in a bottle cage?

[Diggy18]

I always thought that dehydration, hunger, and tiredness can significantly increase your hypothermia risk.

Getting that deep down bone cold is no fun, man. It's like your body can only perceive "cold" down to a certain point, and then it just makes you feel tired and sick. When you feel like your internal organs are cold, then you know you're heading for trouble.