Two things combined to get me in trouble on that chilly March day.
First, I wasn't dressed properly.
I had on blue jeans, cotton socks, cotton underwear, a cotton T-shirt, a long-sleeved flannel shirt, a medium-weight jacket and a mesh baseball cap. The misty drizzle dampened my clothing, and the long boat ride down the river exposed me to 30 mph winds that quickly stripped heat from my body.
Second, I underestimated the conditions.
The air temperature that day was in the high 40s, but the rain and wind effectively made it colder. Had I not been fishing with an observant physician, the outcome might have been much worse.
The best way to avoid hypothermia is to stay warm and dry.
To accomplish that, experts say to dress in several relatively thin layers and to avoid wearing cotton. With those guidelines in mind, here's how I should have dressed for my Cave Run trip:
For a proper base layer, I should have worn two pairs of thin wool socks, long polyester underwear and a long-sleeved polyester undershirt.
My outer layers should have included a pair of nylon wind pants, a thin wool sweater, a water-shedding medium-weight jacket and a wool stocking cap. And for the boat ride downstream, I should have donned a rain suit.
It only took one brush with hypothermia to make me very, very careful about dressing properly for winter outdoor activities. I've waded trout streams when snow was on the ground. I've taken 20-mile bike rides on 45-degree days. I've attended football games where the snow was blowing sideways.
I haven't yet been cold. Dress as I do, and you won't be either.