By Vince Gerasole

(CBS) – Thirty minutes — that’s all it takes in temperatures like this to get frostbite.

Chicago doctors tell us dozens of people are showing up at hospitals with serious injuries from the cold. You might be surprised how they treat it, CBS 2’s Vince Gerasole reports.

The temperature differences between flames and Arctic blasts are drastically different, but exposure to either can lead to similar damage.

“Most burn units actually take care of frostbite,” says Dr. Stathis Poulakidas of the Stroger Hospital Burn Unit.

“It’s like a more severe burn,” he explains. “If you look at degrees of burn, it’s like a fourth-degree burn where the bone and muscle actually are injured such that amputation is frequently necessary.”

After a nearly two-week stretch of dangerous temperatures, the burn unit at Loyola University Medical Center is now treating 18 frostbite patients.

“We are very much over-flowing,” says surgeon Arthur P. Sanford.

In the same period, Stroger’s burn unit treated 26 frostbite cases.

“We’re very concerned,” Poulakidis says. “For these patients, it’s horrible.”

He and others worry that it could get worse if the weather continues its current trend.

One treatment difference, doctors typically use a system that pumps warm air into a plastic sheet to help increase a frostbite patient’s body temperature. Otherwise, daily dressing changes, pain medication and antibiotic creams are identical for burn and frostbite patients.

“The difference between a burn and a frostbite, you don’t operate right away on frost bite,” Loyola’s Sanford says.

That’s because it may take longer to know the extent of the injury.

One of the worst things we can do at home if frostbite is suspected is immerse the wound in hot water. Damaged tissue may not notice scalding temperatures and more injuries may occur.

Get to an emergency room as fast as possible.