The annual Polar Bear Plunge at Boulder Reservoir has attracted New Year's Day nutters since at least 1983, and as a tradition, its appeal is elemental. Freezing temperatures shock the body into a state of fever that is briefly invigorating. If it's cold enough, your heart rate and blood pressure will skyrocket, you'll begin hyperventilating involuntarily for a few minutes, and some of you will become acquainted with the Seinfeldian phenomenon of "shrinkage." After that, and a hop into the hot tub, things will be looking up for the rest of the year: It's what the Polar Bear Club people call a "reset."
Cold-water dips and dousing have a long spiritual and ascetic history around the world, and the icy swims are allegedly good for stimulating the brain, stirring the psyche and releasing stress. They're also a hell of a hangover cure, for those of you planning on partying like it's 1999. American Medical Response is an event co-sponsor and will be on hand with an ambulance in case youre not polar bear enough for the cold (or if you need your stomach pumped from the night before after all). Brrrr.