Warming trend

Clothing that generates heat for the wearer and works for the construction industry could be closer than you think

It was a good idea. Several years ago, a research scientist at the Alberta Research Council developed what could have melted the hearts of many an Albertan construction worker-a propane-heated snowsuit that would keep the wearer comfortable and able to work in temperatures up to minus 40 for hours.

The prototype doesn't seem to have gone further but there may be hope on the horizon for heated clothing that is useable by the construction industry.

It would be especially welcome at work sites throughout Alberta, where temperatures frequently reach 20 - 40 below during the winter months.

Heated clothing has been around, primarily for the motorcycle enthusiasts, for more than three decades. It makes sense for motorcycle riders because you can use the motorcycle battery to provide the juice needed to produce the heat. The problem has been getting the same kind of warmth onto the backs of those on two feet. Although products are available, there are those who say they simply don't work.

"Everybody in the industry wants to ignore science," says Mike Coan, president of Warm & Safe Heated Gear LLC, one of many companies that sell heated clothing, such as battery-heated hand warmers and liners. "People out of China have been doing heated clothing and most of it fails because they all ignore a simple truth, and that is the law of science."

Coan explains that taking the source of power for a piece of clothing from a 12-volt environment like a motorcycle means that you have to carry a 12-volt battery pack, and that's heavy. Going down to a lower-voltage battery doesn't work because reducing the voltage by just one-third reduces the heat produced by two-thirds.

"You have to design clothing that could work with a battery technology that is going to be able to be carried and be practically unnoticed," Coan says. "Because of computers and the radio-controlled toy car industry, battery technology has now moved way beyond what they were five years ago in capacity, lightness and safety."

Warm & Safe is working on designing clothing to work with battery packs that provide a high level of heat and are small enough to fit in your pocket. At under half a pound, the battery pack wouldn't add unnecessary weight either, and it is expected to last a number of hours before needing to be recharged.

The other problem with heated clothing for any type of user, says Coan, is the type of clothing that's being heated. Heating a jacket or coveralls is useless because the heat is kept away from the body by other layers of clothing.

"In our products, the base layer is designed to be up against your body," he says. "The heated areas are bigger so coverage is greater, and the heat is spread out through the base layer-chest, back, neck."

Oh, and heated boots? Coan, who's been working on concepts for improving heated clothing for years, advises plugging in a pair of heated socks instead.

While companies like Warm & Soft work on advancing the technology that would allow clothes to help people deal with the elements, layering up and determining how long it's safe to stay out can help workers get through the winter. And you can always give the heated clothing on the market today a try.

Coan suggests wearing Warm & Soft's heated liner, which is designed to move with the body, under everything to get it close to the body, and using the 7.4-volt battery pack. It would provide 26 watts of heat for about three hours, then you'd need to change the battery. The company is also coming out with new products designed for this purpose that will give you the same warmth for a longer period of time.

Until heated clothing becomes commonplace on work sites it's probably still best to follow the Occupational Safety and Health Administration's (OSHA's) advice for those spending time outdoors during the winter-that is, to dress in layers that can be adjusted to changing conditions.

Also important, says OSHA, is not ignoring the danger signs of uncontrolled shivering, slurred speech, clumsy movements, fatigue and confused behavior.

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