First Degree: Skin turns red and feels very cold.

Second Degree: Skin turns white or very pale, and blisters may appear upon warming.

Third Degree: Area turns black and hard as tissue dies.

FIRST AID

• Avoid rubbing the area, especially with snow.

• Don't walk on frostbitten feet or use a frostbitten hand.

• Avoid thawing the affected area if you are far from help or if there is a chance of refreezing.

• To thaw, immerse area for 20-45 minutes in tepid water; never use hot water.

• Do not put salves or creams on frostbite.

Source: Hennepin County Medical Center