It was a beautiful, bluebird day. I managed to bag a nice mule deer buck thanks to the competence and hard work of my young guide. I was feeling pretty smug as we rode off the mountain, basking in the warm British Columbian sunshine and the sight of my mulie rack on the back of the horse in front of me--but things change fast in the mountains.

Hours short of camp, the weather turned faster than I imagined possible. In an instant, the skies went from clear and sunny to a frightening black. Howling winds brought a cold rain and plummeting temperatures. By the time we got low enough to find shelter in the trees, it had been raining, sleeting and snowing sideways for an hour, and my young guide was hypothermic. Fortunately, I had some good packable rain gear, gloves and a stocking hat. My hapless guide had nothing but the jeans and flannel shirt he wore up the mountain, which were soaking him to the bone. He was shivering, blue and incoherent, but my clothes kept me dry and warm enough to build a blazing fire and makeshift shelter. A few hours later, he was back to his normal self, but we spent a long night and most of the next day huddled in that little shelter while giant, centuries-old trees crashed down around us.

My survival skills came in handy that night, but so did my clothes. Knowing what to pack--and bringing it along, regardless of the forecast--likely saved both our lives.

Layering Basics
It’s no secret that layering is the key to staying warm, but based on the clothes many people bring to hunting camp, few realize that what you layer with is more important in keeping warm and dry than how many layers you wear.

The all-important base layer is worn closest to the skin. Its function is to wick moisture away from your skin keeping you warm and dry. Base layers should have a fairly tight fit, and be of the proper thickness to match the temperature and your activity level.

For example, I wore a thick Under Armour base layer on my arctic grizzly hunt last year because I spent each day on a snowmobile in temperatures that plummeted to well below zero at night, only reaching the thirties during the day. On my upcoming Dall sheep hunt, where temperatures should range from the twenties at night to the fifties during the day, and I will be very active, I’ll take only a thin base layer. However, when I’m hunting from a tree stand in those same temperatures, I would opt for a heavy base layer to offset my inactivity.

For them to be effective, base layers should be made from a moisture-wicking materials like silk, polypropylene, polyester or a hi-tech material like Thermax or Thinsulate. Wool also works, but I’ve yet to find wool I’d feel comfortable wearing next to my skin all day. Cotton is out; those old red cotton longhandles your grandpappy wore are absolutely useless when it comes to wicking away moisture. In fact, cotton is one of the worst fabrics you can wear in cold, wet weather, hence the old North Country saw, “cotton kills.”

The middle, insulating layer traps warm air next to your body and wicks moisture away from the base layer to the outer layer. It should be worn a bit looser than the base layer, but it must maintain contact with the base layer to work properly. Down, fleece, and wool are popular mid-layer materials. Again, the thickness of the layer is dependant on activity level and temperature.