It’s cold: waking up to 9 degree temperature is cold in anyone’s book, no matter how cold-blooded you are, no matter where you live.

But how cold is it? And how does that cold affect us when we venture out?
Understanding what’s going on when your exercising body interacts with the cold is key to figuring out how to deal with frigid conditions. Proper preparation for the cold and being able to read the signs of how your body is reacting can mean the difference between a day of exploring in the winter woods or Netflix. As is the case with so many matters concerning the active outdoor life, a great source of information is Princeton University’s Outdoor Action website. And in the case of matters concerning the cold, their comprehensive “Outdoor Action Guide to Hypothermia and Cold Weather Injuries.”
“Traveling in cold weather conditions can be life threatening,” writes Rick Curtis, who heads the outdoor program at Princeton. “The information provided here is designed for educational use only and is not a substitute for specific training or experience.”
Disclaimer obediently noted, here’s a very quick primer on hypothermia:
Can initially be tipped off by signs of the “umbles — stumbles, mumbles, fumbles, and grumbles which show changes in motor coordination and levels of consciousness.”
Involuntary shivering is a sign of mild hypothermia, slurred speech a sign of moderate hypothermia, dilated pupils is a sign of severe hypothermia, erratic and very shallow breathing is a sign of, well, you don’t want to reach that point.
To deal with the onset of hypothermia you should reduce heat loss by adding clothes, switching to dry clothes if your clothes are wet, move, seek shelter; eat and drink; find heat, through a fire, for instance, or direct body contact.
Learn more about hypothermia as well as vasodilation, vasoconstriction, the pathophysiology of tissue freezing and a whole lot more by visiting the “Outdoor Action Guide to Hypothermia and Cold Weather Injuries.”