We’ve come a long way from the days of heavy winter coats and layers upon layers, meant to keep Jack Frost’s nip away from your nose.

No longer must we spend an equal amount of time getting ready for outdoor activities as we do actually performing outdoor activities.

Thanks to technology (and more common understanding of our own bodies) we can now keep winter’s chill at bay and remain flexible enough to exercise outside during North Idaho coldest season.

Before I get into actual clothing, we need to understand the science behind warmth. Heat transfers in two ways: Conduction and convection. If the transfer of heat involves two solid surfaces, the direct contact leads to conduction. If a mass (i.e., your body) encounters a moving fluid or gas (i.e., a cold wind) then convection is in play.

So when you come in contact with a cold surface, the conduction causes your body to lose heat, transferring it poorly to that surface.

I remember camping during Boy Scout outings, where after pulling up stakes and removing the tent, you could see from the underlying surface (usually snowy ground) exactly who lost the most heat, leaving the largest imprint and snow valley.

But back to heat transfer. As a cold wind wraps around you, heat is lost depending on how well you are prepared for its effect. The better the barrier, the less heat you’re going to lose.

And by better I don’t mean thicker. But layers are still in.

The layer closest to your skin is called the base layer. This layer is responsible for preventing conductive heat loss. For decades, long, thick underwear was commonly used, but today many good options are available. Merino wool or undergarments made of “wicking” material are useful, depending on what exactly it is you plan on doing. Sweating (or at least the ability of your undergarment to rid your skin of sweat) also robs your body of heat.

If you’re exerting little physical effort, but must be outside for an extended period of time, layers still work well to insulate the body from the effects of cold. However, if you will be performing even moderate physical activities, staying warm depends on the ability of your clothing to pull moisture away from your body while maintaining the right level of warmth.

Also, luckily, advancements in clothing materials have enabled us to wear lighter outer layers while providing a more affective barrier to heat loss. Also, present-day hats, caps and gloves do a much better job of heat management than their predecessors.

Until you get a good handle on what materials and layers work for you, the trial and error can be dangerous, if the warning signs are not heeded. Shivering, for example, means your core temperature is falling. It’s your body’s way of telling you that bad things will happen to you unless you get to someplace warmer quickly. Shivering consumes calories in the body’s attempt to generate heat that is being lost by either conduction or convection.

Mild hypothermia will set in soon after shivering starts, depending on the person. Some have a long tolerance, some shorter.

Once shivering is no longer effective, the body stops the process and moderate hypothermia sets in.

Other than proper apparel, calorie consumption can also help in warming the body. You tend to handle the cold better, as a rule, if you had an adequate caloric intake. Keeping your blood sugar up and staying hydrated are also of utmost importance, allowing you to tolerate exposure to cold than those with deficiencies in those areas.

The more time we spend outdoors, the more our bodies get used to the lower temperatures. As a result the body resets itself to respond to the cold at increasingly lower temperates. Likewise, during the summer, the more time you spend in the sun, the higher your skin temperature must get before you sweat. Scientists are studying a type of body fat called brown fats, which may be responsible for the body’s ability to “reset” its cautionary temperature.

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Jerry Hitchcock can be reached at 664-8176, Ext. 2017, via email at jhitchcock@cdapress.com, or follow him on Twitter at HitchTheWriter.