CHICAGO — The heat just came on and the system is blowing warm air into my kitchen. If I head outside, I will step into my garage, start the car and within a few minutes the heat will warm the vehicle.

While this all sounds comfy cozy on a day when the temperature is in the high teens, the wind is whistling and snow coats the back deck, it just might be my worst enemy.

Lulled into a false sense of body heat, as a result, I may go out without a hat, without my gloves, wearing street shoes and thin socks. Heck, there's no maybe about it. I do that all the time. Perhaps that's why it is so easy to venture into the outdoors without wearing or carrying enough gear to ward off cold.

If there is snow on the ground and you know you will be standing outdoors for long stretches of time, you are more likely to pack sensibly, wear a heavy coat and slip on the best boots you possess. But it is easy to be fooled going from the house to the car to the outdoors. There is about a 90 percent chance that standing still on a frozen lake while ice fishing is going to make you cold.

There is at least as much danger going hunting, fishing or hiking in medium-cool temperatures of 40 or 50 and getting caught in unexpected wind or rain.

"Hypothermia is the No. 1 killer of outdoor recreationalists," said Mike Capps, an outdoors products expert from Missouri and a former emergency medical technician.

"Cold kills in two steps — exposure and exhaustion."

Early in the fall — when the weather was mild — I attended an outdoor writers' gathering in South Dakota. One focus was on being prepared for outdoor winter activities.

"Never ignore shivering," Capps said. "That's your body's first sign of, 'I have to do something.'

"Plan ahead. That's what kills most people. They think, '`I can tough it out.' They don't bring anything dry to change into. If you're sitting in a hunting blind and you're cold and wet with the wind, that's one of the biggest dangers for guys in the outdoors. Being soaked in sweat is just as bad."

Shannon Hanson, an outdoors equipment saleswoman at Sportsman's Warehouse in Sioux Falls, is a sleeping bag know-it-all. She said temperature ratings are general at best. The type of bag, what people wear and how they move around when they sleep affect comfort zones.

"Mummy bags are conservatively rated," Hanson said. "I have a 30-degree, mummy-style bag that I've taken out in 10 degrees and been perfectly comfortable with it. I have a rectangular bag rated to 5 degrees and I froze my butt off in 30-degree weather."

One thing to watch for when going to sleep is making sure the zippers are zipped all the way to preclude a draft. It is also wise when camping to bring a reliable air mattress that keeps the bag out of contact with the cold, hard ground, she said.

"If you are sleeping directly on the ground, you will lose a lot of heat," Hanson said.

Until recently, campers threw down sleeping bag pads and dropped the bag on top. Although it is an obvious idea, people now are sliding pads inside their sleeping bags.

"That pad will provide you with the insulation and the pad isn't going anywhere," she said.

Hand-warmers have been around a long time, but someone always is trying to build a better mousetrap. Optronics of Oklahoma has attempted to do just that by introducing "Firepod Handwarmers" to the marketplace this winter. We are all used to stuffing hand warmers into our pockets, breaking the packaging open when needed, and then discarding the warmers when effectiveness wears off.

Meet the rechargeable hand-warmer. For as little as $20, according to Optronics product rep Gary Hollohan, you can buy fleece warmers that are powered by AA batteries and can be recharged and reused. Each cycle is good for about five hours.

"It's an alternative to chemicals," Hollohan said. "I had the occasion to use them twice. I was extremely cold on a boat when the temperature was in the upper 30s. And another time I was out all day."