Boating safety experts are warning that cold water can kill.

With the fishing season opening May 15, the Minnesota Department of Natural Resources reminds anglers that even on a warm day, water temperatures can hover in the low 50s. The Coast Guard says a boating accident is five times more likely to be fatal if the water is colder than 60 degrees.

Tim Smalley, DNR boating safety specialist, says cold water can kill in ways you might not expect.

Victims who fall overboard can suffer cold water shock, which involuntarily causes them to take a big breath. If their head is underwater, they can drown immediately.

For people lucky enough to keep their head above water, unless they’re wearing a life jacket, drowning will occur long before hypothermia gets them.