(CNN) A winter storm system that dumped snow across the Great Lakes region and New England has moved out to sea, but that doesn't mean the frosty weather went with it.

The East Coast should brace for temperatures to plummet. Even in sunny Miami, it's predicted to get cold enough to stun the iguanas.

Yet as cold as it is, for many, it feels even colder. Roughly 10 million people, from Montana to Illinois, are under wind chill advisories with the northern Plains and Midwest experiencing temperatures that "feel" between 20 and 40 below zero.

A resident trudges through heavy snow in St. John's, Newfoundland, on Saturday.

Such wind chills can cause frostbite on exposed skin in as little as 10 minutes.

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