Someone I don't know called Kieran has ice-bucket-challenged me. And while I'm fairly sure that anyone
who's going to donate to ALS -- motor neurone disease is a rough translation in the UK -- has
already donated, well, it would be rude to refuse.
Only I figured I'd teach something as well, so I have not a bucket, but a bathtub full
of very cold ice water and a heart rate monitor. Which is currently showing 112, because I'll
be honest, I'm not looking forward to this. And you'd expect that getting dunked in ice
water, or getting it specifically on your face, would start a fight-or-flight response,
an adrenalin response, but that's not the case.
What it does is activate something called the Mammalian Diving Reflex. Something that
most mammals have, to one extent or another, and humans still have thanks to a quirk of
evolution being held over millions and millions of years.
If you get cold water on your face, what happens is that your heart rate goes down. Seriously.
Blood gets pulled in from all your extremities just to keep the heart and the brain alive
and working. Because, for all your brain knows, you might have to be there for a very long time.
So. 108. Let's see what happens.
(PANICKED BREATHING) Wow. That...
is...
incredibly unpleasant.
And my heart rate... is 91.
There you go. Mammalian diving reflex. Actually works. And now I'm going to move my phone
away from the cold water and I am going to turn a hot shower on. Because it's really
cold in here.
I can now feel the blood coming in from my extremities because my hands and feet are
absolutely numb. And I am just going to turn on a...
Oh god that's also cold. Agh!
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