This is the first day of winter — and the extreme cold most Iowans are seeing can cause frostbite in a matter of minutes. That malady is one which many people hear about but often don’t understand until it’s too late.Sharron Townsen is with the Mercy Family Healthline in Mason City. She says people who have to go out should dress appropriately.Townsen says frostbite can be painful, and in severe cases, can result in the loss of fingers and toes. the symptoms include losing feeling in a body part followed by redness and swelling as it warms up.Townsen says people who are at-risk of having a severe case of frostbite should get medical help right away.