ANCHORAGE, Alaska - For thousands of years, the Plains Indians heated their tents with fire. The drafty teepees they called home were basically designed to wrap around a firepit. The teepee had a big opening in the roof to let out smoke and fumes and a loose-fitting door to let in plenty of oxygen.

A hundred years ago in the Alaska Bush, miners and trappers who roamed the wilds lived in heated tents. Archdeacon Hudson Stuck carried a tent and a stove in his sled on his 10,000 miles by dog sled across the state. The Sourdough Expedition that nearly reached the summit of Mount McKinley in 1910 packed tents, wood stoves and wood almost two miles up that mountain.

Their tents were but a small improvement on those of the Indians. They closed them up more to get rid of some of the draftiness, but made sure to vent the fire.

Fire was a friend to these people in the cold arctic night. Heat was one of the few luxuries they knew.

Were they to return to Alaska today, it might shock them to learn that the warm, heated tent is no longer a friend - but a deadly enemy.

Recently, a charcoal grill used to heat a tent near Circle Hot Springs north of Fairbanks killed two men.

Last fall, a propane heater used in a tent near Tok killed a moose hunter from Iowa camped along the Taylor Highway.

In 1994, a propane heated tent nearly killed five mushers in the Iditarod Trail Sled Dog Race.

Eight years before that, a tent heated with a butane stove killed two Swiss climbers at 14,000 feet on Mount McKinley.

Blame technology.

Blame human thoughtlessness.

Blame what you will, but recognize these are tragic and unnecessary deaths.

Part of the problem is that there are so few tents on the market these days designed to operate with stoves; most of those available are old-fashioned, cotton wall tents.

Cotton is heavy and subject to rot. Most of the stoves designed for use in wall tents are likewise heavy. Nearly all of them burn wood, which is time-consuming to collect and somewhat dirty to burn.

Most major manufacturers abandoned wood-stove heated tents decades ago and gave up cotton in favor of nylon or polypropylene. These fabrics are lightweight and resist rot, though most of them will break down in sunlight.

What they will also do is burn - easily and rapidly.

For that reason, most manufacturers avoid making accommodations for heat in their tents. Overtly encouraging people to heat today's tents of nylon and polypro would significantly increase the likelihood of tent fires.

A tent fire would sooner or later kill somebody, and then the tent manufacturer would probably be looking at a massive lawsuit.

If you are a tent manufacturer, this is a good reason to avoid heated tents like the plague.

The public wants lightweight, durable tents. Give the public what it wants. And if people die or nearly die trying to heat these tents with camp stoves, propone heaters or, in the most recent case near Fairbanks, a charcoal grill, it's their problem.

Most tent owners understand this. Others, obviously, don't.

All they seem to know is that it is as cold inside an unheated tent today as it was 100 years ago, so they do what they can to warm the tent. Since there is no convenient way to put a vented wood stove in most modern tents, people turn to easier, apparently cleaner, or simpler methods of heat.

They fire up a propane heater, a camp stove or even, as in the case of the men north of Fairbanks last week, a charcoal grill. All of these devices produce carbon monoxide.

Carbon monoxide is an odorless, tasteless gas given off as a byproduct of combustion.

Your blood loves carbon monoxide. Scientists calculate that your blood's attraction to carbon monoxide is 210 times stronger than your blood's attraction to oxygen.

Because of this, carbon monoxide quickly replaces oxygen in your bloodstream. Your brain begins to starve from lack of oxygen. You get dizzy and nauseous. Eventually, unless something is done to get rid of the carbon monoxide, you die.

According to U.S. authorities, carbon monoxide is the leading cause of poisoning deaths in the United States.

Alaska, according to an American Medical Association study, led the nation in per capita carbon monoxide deaths in the 1990s. Alaskans perished in tents, cars, houses and who knows what else.

One man died in a hunting shack on the Kenai Peninsula some years ago when a charcoal grill was brought inside to provide heat in the fall. Charcoal fires are among the biggest producers of carbon monoxide.

Everyone ought to know that, but it's obvious from the deaths around Alaska each year that some don't. As a species, we seem to have forgotten what the sourdoughs knew and before them the Indians and before them, quite possibly, the cave men:

Fires need to breath, or they will kill you.

Fires need a place to exhale bad air (a stack) and a place to inhale good air (a vent).

Without those things, fire fills the air with its waste (carbon monoxide and carbon dioxide) at the same time it is sucking the oxygen out of the air to maintain itself.

If you are in a tightly-closed tent with a source of fire, be it a smoldering charcoal grill or a seemingly clean-burning propane stove, that fire is pumping your environment full of poisonous gas at the same time it is sucking out the oxygen you need to breath to survive.

Time and time again, this has proven a deadly combination. It is unfortunate that there are any who fail to understand. Don't let yourself be one of them.

(Rewritten with the permission of Anchorage Daily News)