With temperatures warming up this week, there is a renewed warning about a dangerous and deceptive layer of ice forming along Lake Michigan

Marissa Perman joins us with why rescue officials say staying off the ice could be a matter of life and death.

What may look like solid ice along the shoreline is actually known as shelf ice, and safety officials said it's unstable, especially as temperatures rise.

"There is no such thing as walking on safe ice, especially here," said Chicago Fire Department Dive Chief Jason Lach. 

'Tis the season for shelf ice, according to Chief Lach. His team trains for rescues along Lake Michigan.

"You never know where it's going to be at. You can't always see it. It's dangerous to walk on," he said.

Shelf ice forms along the shoreline but is not connected to solid land. Experts said it can crack, collapse, or break away without warning. 

Even with what Chief Lach calls "lily-pads" lining the 31st Street boat harbor, that should serve as a warning.

"We've had incidents in the last few years where people are a half mile offshore and were having to go after them because, one,  they didn't know they were on ice, two, they're like, man, it's slippery. It happens," he said.

live cameras from Spyglass Hill in Holland, Michigan, Surf Grand Haven, and the Dempster Street boat launch in Evanston—all show ice shelves, which Dave Benjamin from the Great Lakes Surf Rescue Project said can be tempting to the uneducated eye. 

"It looks magnificent, it is enticing," he said. "I'm at the beach, I've never seen this before, but you could fall through, and if you do fall through, are you going to be in ankle deep of water or are you going to be chest deep in water?"

Videos posted to social media show people, including a man almost falling on the shelf before rushing back to his group for safety, and a small child slipping while walking over the ice alongside an adult.

These dangers increase with unseasonable temperatures when melting weakens the ice even faster. However, it's something you can't see until it's possibly too late.

"When you're living it, when you are in that moment of that very extreme cold water, it's going to cause a lot of panic," Benjamin said.

Rescue crews said no photo, video, or thrill is worth the risk, saying the best bet is to stay off the ice.

Officials are also reminding the public that if you see someone fall through the ice, do not go after them. Call 911 immediately and wait for trained rescue crews.