Tuesday, 26 August 2014

The Ice Bucket Challenge: Scientific Considerations

If you’ve spent any time on the internet over the past couple weeks you’ve probably seen a bunch of viral videos of people dumping cold water on themselves to raise money for ALS. Dubbed “The Ice Bucket Challenge” it is a silly activity for a good cause and there is a lot of science involved, so naturally we’ve decided to volunteer our illustrator to take the plunge (donate at http://www.als.ca/en/donate). There are however a few things to consider before engaging in this frozen fund-raiser, so let’s take a moment to get the facts straight.


The Gasp Reflex

According to Beyond Cold Water Bootcamp there are 4 stages of cold water immersion:
  • Cold Shock Response
  • Cold Incapacitation
  • Hypothermia
  • Circum-Rescue Collapse

While each of these is important when you’re pulling unlucky fishermen from frigid arctic seas, only the first really applies to The Ice Bucket Challenge. The cold shock response lasts for about a minute when you’re actually submerged and it can wreak havoc with your body. It begins with a sudden inward gasp that evolution has programmed as a reflex to help us hold our breath. Unfortunately it can also lead to inhaling a bunch of water, so watch out for it.


Icy Heart

The Cold Shock Response also has serious effects on your heart. A sudden influx of cold water makes your arteries narrow in a process called vasoconstriction. The result is that your heart has to work harder to pump the same volume of blood. The lesson here is, if you have a heart condition, maybe leave the ice buckets to the rest of us and just help out with a donation to the ALS association.


Spicing Things Up

As a reader of this blog, you might also be tempted to throw your own flare onto the Ice Bucket Challenge using some clever science twists. You could try The Dry Ice Bucket Challenge. Dry ice is frozen carbon dioxide and has a surface temperature of -78.5 degrees Celcius (-109.3 F). This makes it a pretty bad choice for our purposes. Being that cold, it has the ability to severely damage your skin. Another reason to give it a pass is that as dry ice warms it sublimates, meaning it turns directly from ice into carbon dioxide gas. This has a cool effect at Halloween parties, but it isn’t something you want to be breathing in while you try to go viral.


Another equally bad idea is using liquid nitrogen. With a temperature of -196 C (-320 F) liquid nitrogen is probably the coldest stuff a normal person can get their hands on. However, unless you want your hands to shatter getting liquid nitrogen on them is a pretty bad idea. If you don’t end up effectively turning into glass by freezing yourself solid you might accidentally cryogenically freeze yourself. This isn’t as cool as in the movies. Rather than waking up in the future, your cells will all rupture as the water in them freezes and expands and you’ll just become a very brittle corpse. You do have about a second before it contacts your skin thanks to the aptly named Leidenfrost Effect, but is it really worth the risk?


No Pain, No Gain

Finally, The Ice Bucket Challenge has the potential to cause you some brief pain. In studies of pain tolerance, psychologists and the Mythbusters alike have used tubs of ice water to inflict suffering on their volunteers. In the long-run a little momentary discomfort is nothing compared to ALS, though; so if you don’t have a heart condition and aren’t dumb enough to try our previously mentioned ice alternatives, we challenge you to go for it!

Without Further Adieu…


References:

http://science.howstuffworks.com/life/genetic/cryonics2.htm

No comments: