Authorities are stressing safety as people venture out on Michigan's lakes, rivers and ponds for ice fishing and other winter recreational activities.
State Natural Resources marine safety and education supervisor Lt. Andrew Turner says "ice is unpredictable" and people should "always assume that it's unsafe."
On Thanksgiving, authorities in Macomb County's Shelby Township rescued a 38-year-old man and 11-year-old boy who fell through thin ice on a retention pond.
The U.S. Coast Guard responded last winter to 62 ice rescues on the Great Lakes, saving more than 50 lives.
Hypothermia -- when a person's body loses more heat than it can generate -- is a major threat when someone falls into frigid water.