Brr! Can Frigid Temps Lead to Weight Loss?

Dec. 15, 2010— -- Finally, an upside to the frigid temperatures that have gripped much of the nation -- all the shivering could help shed a few pounds.

"The body wants to maintain a balance, a homeostasis of 98.6 degrees," said author Tim Ferriss, who promotes this type of "thermal dieting." "If you make it cold, the body will do everything it can to get back to 98.6. And it has to burn calories to do that -- heat equals calories."

Ferriss, the best-selling author behind "The 4-Hour Workweek" and the just-released "The 4-Hour Body," is known for his lessons on how to manipulate the body to your advantage.

Using winter to lose that winter weight is just one example. He said people can burn up to 50 percent more calories by exposing themselves to below-freezing temperatures, which causes the body to work overtime.

"There's actually a type of fat called brown adipose tissue -- BAT," he said. "Cold can trigger this BAT. It actually produces heat, and you burn fat tissue."

Ferriss' advice is backed by science.

"We can use the thermal environment to supercharge our weight loss," said former NASA scientist and entrepreneur Ray Cronise.

Cronise has researched the effects of temperature on astronauts and said there is evidence that cold can go a long way in speeding up a person's metabolism.

"In environments as mild as 60 degrees, some of these people saw metabolism rates boost by as much as 20 percent," he said.

But Dr. David Katz, director and founder of the Integrative Medicine Center and professor at Yale University, was doubtful and said if people were really that desperate to lose weight, they should just try diet and exercise.

He also warned that exposure to extreme cold, especially through ice baths, could cause complications in people with cardiovascular problems or even induce cardiac arrhythmia in those at risk. Ferriss himself also notes in his book that readers should consult a physician before attempting some of these techniques.

Thermal Dieting: Drink Ice Water, Lose the Sweater

Cronise had himself been struggling to lose weight through a traditional diet and exercise regimen, saying he made it to 12 weeks and then "hit a wall."

So he added a thermal element and tripled his rate of weight loss, losing 30 pounds in six weeks.

Small changes, he said, work best. Even just drinking ice water first thing in the morning can rev up the metabolism.

"Think about carrying that sweater," he said, "instead of wearing it."

Here are some at-home tips to try thermal dieting:

Place an ice back on the back of your neck and on your upper chest for 30 minutes while reading or watching TV to rev up your metabolism.

Take cold showers: Ferriss advises taking 30-minute cold showers for the maximum benefit but shorter showers help too.

For an abridged version, gradually lower the temperature in the shower to 68 degrees over the course of five minutes, then stand in the cold stream for two to three minutes straight before getting out.

Immediately upon waking, start drinking ice cold water and continue sipping ice water throughout the day.

Go for "chill walks." Make sure to bundle up extremities such as your hands, feet, ears and head, and then go for a walk in the cold in summer exercise attire. Consider working up to this kind of walk by slowly taking off layers of clothing. Be sure to carry your coat with you, so that you can warm up should you become too cold.

ABC News' Courtney Hutchison contributed to this report.