MIAMI (CBS4) — We’ve all heard of the low-carb diet, and the high-protein diet. But what if all the exercise and healthy eating wasn’t enough? Could adding “cold” to your life help you lose that unwanted fat? Some people say it can if you follow the “ice diet.”

Tim Ferriss, author of “The 4-Hour Body,” takes three ice baths a week loading 20 pounds of ice into his bathtub. He calls it thermal loading, others call it the “ice diet.” He says it helps get rid of unwanted fat.

“So your body wants to be 98.6 degrees and if your body temperature is lower, it will do everything it can to get back to 98.6 degrees,” said Ferriss. “It burns calories as heat and most of those calories come from fat.”

Ferriss says he advises people to start slowly, first trying ice packs on the back of the neck before moving on to cold showers. If you can handle that, maybe you’re ready for an ice bath.

Former NASA scientist Ray Cronise says he lost 30 pounds in just six weeks.

He says the aerospace industry has studied the issue of people losing weight when exposed to cooler temperatures. He worked out in cooler temps, wore fewer layers, turned down the thermostat, slept without covers and would take walks without bundling up.

But does this science hold water?

Dr. Stacey Ingraham studies exercise physiology. She says Ferriss has his science backwards because cold actually slows down metabolism.

“To burn the most calories, sauna and room temperature — not cold water immersion,” Ingraham said.

She adds: “Long-term exposure in cold water can start lowering your core body temperature, and that can be very dangerous.” Severe cold temperatures can also be a problem for people with heart conditions.

Will people really go for the ice diet?

Dieter Gillian Hobson says she’d do just about anything to lose weight, but when she tried the ice bath, she couldn’t do it.

“I think that’s the most painful thing I’ve done. I got halfway down and it was too cold.”