science

PPFF#148:Hypothermia

Good morning,

When I arrived in this lovely northern Scottish city of Aberdeen this week, the temperature difference between London and Aberdeen was very noticeable 11 degrees (though it felt more like 20); that in Aberdeen being -3 degrees. Believe it or not, the week before, the captain of the Aberdeen-bound flight I was on, announced, as we landed, in an (understandably) incredulous tone, the temperature was +15 degrees – all the more reason for being so ill-prepared for the shock to my system as I walked out onto the aircraft jetty. That was long 15 metres from those steps to the entrance of the airport. Luckily that walk only lasted a few seconds.

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As we approach December (and what looks set to be a cold winter), I thought maybe I’d do a public safety announcement about hypothermia – sort of.

While reading about hypothermia, I learnt about something called ‘pre-terminal-burrowing, paradoxical undressing’, which sounded pretty insane. Basically, hypothermic humans make an instinctive last ditch effort to minimise heat loss, by burrowing into a tight enclosed space much like hibernating animals. Hence, the term ‘terminal burrowing’. In urban settings, this ‘burrowing’ happens in closets, large bins, under beds etc. – strange but nothing that defies immediate logic; cold-> minimise heat loss -> reduce surface area-> burrow.

‘Paradoxical undressing’, however, is rather puzzling to say the least; it’s a behaviour observed in many victims of extreme hypothermia (as many as 50%!) of undressing, removing most or all items of clothing, which speeds up heat loss. This happens apparently just before terminal burrowing. From what I’ve read, this is explained by the body’s reflexive mechanism called ‘vasoconstriction’, which contracts blood vessels to minimise heat loss from the body surface. But then after a while the muscles engaged in contracting the blood vessels collapse from overworking and this causes warm blood to rush from the core to the extremities, fooling the confused hypothermics into feeling really hot (I’m guessing similar to feeling warm after a few drinks in the cold) – so they get naked and burrow and (mostly) die.

So if you ever end up in this unfortunate situation, having hypothermia, remember, even if you feel hot, you’re not! (also might apply when you’re looking too intensely in the mirror) So don’t get naked. Wrap up and burrow.

Have a warm Friday!

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