Field Water Disinfection

Field Water Disinfection

Ensuring clean, safe, potable water is increasingly difficult, as polluting agents become more widespread, and danger may lurk within even seemingly pristine water sources.  Today's entry discusses some contaminants commonly found in the North American backcountry, some techniques for removing them, and the perhaps-not-surprising role of basic hygiene in preventing contamination and GI illness.

Recommended Musical Accompaniment: The Yardbirds, "Drinking Muddy Water"

Surviving A Night In The Outdoors

Surviving A Night In The Outdoors

Surprisingly few people seem to understand how easy it is to wander away from an unfamiliar trail - even a well-marked one - or the risks of an unexpected night outdoors.  Many survival books and websites begin from the assumption that you are warm, hydrated, nourished and thinking clearly: unfortunately, by the time you realize you are in trouble, this is unlikely to be the case.  However, with only a few preparations, you can greatly improve your chances of surviving the night in relative safety.  

Cold Water Immersion - As Bad As It Sounds

When teaching our wilderness first aid courses, I often find I don't have time to talk about all the things I'd like to.  One topic that rarely gets the attention it deserves is cold water immersion.  Fortunately, the much-ballyhooed Dr. Gordon Giesbrecht has - of course - got us covered.  

Check out coldwaterbootcamp.com, to see what happens when 9 volunteers - who cannot have fully understood what they were getting themselves into - are subjected to 6° C water.  The videos are... 

...wait for it...

...chilling.

Of particular interest is Dr. Giesbrecht's 1:10:1 rule , which outlines the critical phases you go through after cold water immersion.

  • Cold Shock: Irregular, very rapid breathing immediately after immersion in frigid water, and lasting for 1 minute.  This hyperventilating breathing pattern will cost you oxygen, increases the risk of taking in water, and tires you out quickly.  Concentrate on controlling breathing and keeping your airway clear.
  • Cold Incapacitation: During the next 10 minutes, you will lose motor control of your hands, feet, arms and legs.  Concentrate on self-rescue, or finding some way to keep your airway clear.  Otherwise, if you aren't wearing a life jacket, you will likely drown. Fun Fact: If you have fallen through ice and don't have the strength to pull yourself out, you can put your arms and upper chest on the ice and allow them to freeze there, protecting your airway until help (hopefully) arrives.  I told you it's as bad as it sounds.
  • Hypothermia: It can take up to an hour for unconsciousness due to hypothermia to occur, even in very cold water.  This is very dependent on body type and prevention measures - information that you should definitely check out on Dr. Giesbrecht's website!  

As for assessing and treating hypothermic patients, check out our blog entry on just that subject.

Stay warm!

Bear Awareness

And now, bears.

The subject of bears always makes me think of a bumper sticker I once saw, "Whatever doesn't kill you makes you stronger. Except bears. Bears just kill you."

One of the most common recommendations from students is a greater focus on wildlife encounters (bears) during the WFA course. While I have recently added more material related to treatment of injuries from animal attacks (bears), there just isn't time in class to adequately prepare students to avoid or manage a wildlife encounter (with bears).

One great resource is the Wilderness Medical Society's excellent 3-part article, 'Of The Family Ursidae.' Great information, and some very cool video footage (of bears) as well.  You can find this excellent online course at

https://wms.org/magazine/1193/Of-the-Family-Ursidae

And, yes, I know that bears aren't the only wildlife hazard. Comprehensive Wildlife Awareness courses are available, and I am more than happy to dig up some of those resources in the future.

In the meantime, tell us about your wildlife encounters or near-misses - and, no, it doesn't have to be all about bears.