CHICAGO (CBS) — If you don’t take seriously the deep freeze blanketing the Chicago area the past couple days, you do so at your own peril. Frostbite and hypothermia are real threats in this weather.

“We see a few cases. People are working outside over long hours. They didn’t really realize they may have not paid as much attention to the fact their fingertips were a little bit numb, and it’s not until that goes on for another couple hours they realize, boy this has become painful,” said Dr. Paul Casey, an emergency medicine specialist at Rush University Medical Center.

READ MORE: 'What It Takes To Convict': A Former State Prosecutor And Retired Judge On The Derek Chauvin Verdict

For early-stage frostbite and hypothermia, you should gradually warm a frostbitten body part. Whatever you do, don’t put a frostbitten body part in hot water, as you could burn your skin.

“You don’t want to be out for long periods of time, because if you’re ignoring those warning signs, that’s when you’re at risk of even further damage, and even damage to the point that … your circulation won’t return,” Casey said.

READ MORE: Law Professor Sharon Fairley: Derek Chauvin Verdict In George Floyd's Death Will Be 'Defining Moment' For Many Young People, Sends Message About What's Possible In Chicago

Amputation might be necessary in severe cases.

Hypothermia involves your actual body temperature dropping. Early signs include shivering, slurred speech, and being confused and uncoordinated.

MORE NEWS: Anxiety, Then Relief At South Side Shoeshine Shop As Guilty Verdict Is Read Against Derek Chauvin In Death Of George Floyd

If you do notice symptoms of hypothermia, you should call 911, and get inside to gradually start warming up.