Issue 32 - The article on hypothermia P 65

[HarveyCamm]

I'm confused about the 'Breathe right' advice - what's the purpose of this - take 30 deep breaths while exposed to extreme cold? I'd have though that filling your lungs with extremly cold air wouldn't help hypothermia or is it the use of the muscles to generate some heat?

Does anyone know what this is supposed to do please? :S

Harv

[ttproducts]

Shallow breathing is a natural effect of hypothermia and that reduces oxygen in the blood, leading to reduced energy and brain activity n stuff. I don't know for sure but I'd have thought making a conscious effort to breath properly will help delay the onset of more serious symptoms - one of which would be even more shallow breathing or no breathing at all and that's never ideal.

[Redmurty]

if yu have hypothermia you wont have a clue what your doing. Worrying about breathing is usually the last thing on their mind

cheers Spud

[AndyB]

Surely the point is to avoid ending up with hypothermia?

The only tip I was ever given (apart from the blindingly obvious)to avoid hypothermia was to eat & drink little and often.

Somewhere around the house I've got my old company handbook that showed exposure times at various temperatures done as a graph so you could factor in wind chill and you don't get very long before exposed flesh freezes. The good thing is that above a certain speed the wind chill factor stops increasing so just go faster and it won't hurt you any more (thumbs)

[Redmurty]

Surely the point is to avoid ending up with hypothermia?


which is correct and makes sense, people behave very interestingly when they have it, and it's usually down to those your with to watch over you if they think your sliding down that path. If your looking after yourself correctly you wont have to worry you'll be taking on fluids ect.

cheers Spud

[Brenhden]

I remember an old episode of Ray Mears in Canada where they got this big lumber jack bloke to sit in an icy shower for about 30 minutes until he got hypothermia. It was not pretty and that guy was not able to take instruction and think about anything.

[Philiptigerrice]

There was some interesting research / theorising done a few years ago about biking injuries & deaths in winter being linked not to icy roads - but due to low level chronic hypothermia (as opposed to acute hypothermia) setting in over several hours of riding. It came about after some unexplained deaths in the USA where investigators could find no reason for the bikers crashing, other than wet temperatures of around 5 degrees Celsius. It was like the victims has nodded off, or just stopped concentrating - and hit barriers / road furniture at not inappropriately high or dangerous speeds.

Reaction times slowing down, zoning out, wriggling about and concentrating on body sensations instead of the road, and generally the temperature acting as a big distraction to safe riding, as well as the physiological impact of lowered core temp is thought to occur.

Chronic Hypothermia is the sort of Hypothermia that little old ladies get, sat in poorly heated houses for long periods, where their core temperature drops slowly over a number of hours - as opposed to Acute Hypothermia which is rapid onset, for example falling in icy water. The muddle headedness and altered sensation that Chronic Hypothermia causes, is why sensible elderly people fail to get up and take action. It often starts as a thinking that - "I'll wait till I put the fire on - I'm tough, I'll give it a while..." and often isn't to do with the fact that they cannot afford to put fires or heating on. Its a bit of a paradox, and its why I never let myself get too bad, when I'm out on my bike.


I've not read the article yet, but I've never heard or read anything about breathing differently being remotely useful to anyone with either form of Hypothermia, in all my years as an Army Combat Medic, NHS Medic, or now as an Offshore Rig Medic... But perhaps its new research?

Acute hypothermia should NOT happen to a fit healthy biker unless you plunge into a pond!


Chronic Hypothermia CAN happen to us. And it is chronic hypothermia that needs to be thought about, planned for - and avoided.

[-Ralph-]

The good thing is that above a certain speed the wind chill factor stops increasing so just go faster and it won't hurt you any more (thumbs)

You seen anything that backs this up Andy? I'm not arguing with it, just genuinely interested in the effects of windchill, as a person who commutes at motorway speeds along the A14 in single figure temperatures. I'd like to know what the outside of my jacket is really exposed to.

[-Ralph-]

There was some interesting research / theorising done a few years ago about biking injuries & deaths in winter being linked not to icy roads - but due to low level chronic hypothermia (as opposed to acute hypothermia) setting in over several hours of riding.

I stop every hour to 90 minutes in the middle of summer. Covering on average 40-50 miles each hour on A roads and 60-70 miles each hour on motorways, it allows me to cover 500 miles in a day's riding with very little in the way of fatigue. I get off the bike at the end of the day feeling like I've been for a Sunday bimble. It just becomes 10 x 1 hour rides along legs of a journey, instead of 1 exhausting and unenjoyable 10 hour journey.

Somebody who doesn't do this in the winter and get themselves indoors with a hot drink at least once every 90 minutes, is frankly in my opinion, missing a few nuts and bolts.

I'm out on the bike all day today, and a change from the recent mild weather means it's 6 degrees outside. So I'll be in base layers, fleece, quilted lining and textile jacket on top, and base layers, quilted lining and textile trousers on bottom. Richa Cold Protect gloves, Coldkillers neck tube, thick socks and Gore-tex touring boots. I'll be toasty when riding, and if I get into slow traffic or stopped for more than 5 minutes, I'll actually start to get too warm.

I do wonder how many of those accidents you mention, the riders weren't dressed properly.

[HarveyCamm]

After TTProducts response it did make me wonder whether it's the 'forgetting' to breath through oxygen depletion and muddle headedness or whether there was anything to do with cold air being more dense and having more oxygen in it and so needing to take less of it into the body. I'm no doctor but I thought that the breathing regulation was so automatic that while you can decide to take a deep breath you don't need to think about the regular stuff so we can do it in our sleep.

Anyways interesting article and I do think that I get less flu type colds in the winter because I ride in every weather except inches of snow so my body is used to getting cold. I've not got heated kit but I do use bar muffs and plenty of layers and I'm aware of the huge difference speed & temperature make with wind-chill.

Stay warm & ride safe everyone. (thumbs)
Harv