Frostbite

DEFINITION

• Frostbite is a cold injury to the skin

Symptoms

• Symptoms of mild frostbite (frostnip) are cold, tingling and painful skin.
• True frostbite causes white, hard, completely numb skin; can be serious, and always requires medical attention after re-warming.
• Common sites are toes, fingers, tip of the nose, outer ear or cheeks.

Cause

• The nerves, blood vessels and skin cells of a part of the body are temporarily frozen.
• The ears, nose, fingers, and toes are most commonly affected.

Frostbite Severity - Frostbite can be classified like burns:

• Frostnip (mild frostbite): Cold, tingling and painful skin
• 1st Degree: White and waxy (hard) while frozen; mild redness and swelling after re-warming
• 2nd Degree: Same as 1st degree plus blisters after 24 hours
• 3rd Degree: Blood-filled blisters progressing to skin damage and scarring

Hypothermia

• Frostbite and hypothermia are two distinct and independent medical problems.
• Frostbite results from a cold injury to the skin. The body's core temperature can be normal.
• In contrast, hypothermia signifies a marked decrease in the body's core temperature, and frostbite may not be present. Hypothermia is defined as a body temperature less than 95° F (35° C) rectally, and can be fatal without intervention.

Factors Contributing to Frostbite

• Medical conditions: Patients with diabetes, Raynaud's disease, and previous frostbite are all at greater risk.
• Type of contact: The frostbite is much worse if the skin and clothing are also wet at the time of cold exposure. Touching bare hands to cold metal and volatile products (like gasoline) stored outside during freezing weather can cause immediate frostbite.
• Duration of contact: The longer the cold exposure, the greater both the heat loss and the likelihood of frostbite. The wind velocity on a cold day (windchill index) also determines how quickly frostbite occurs.

FIRST AID Advice for Frostbite:

Rewarm the frostbitten area rapidly with wet heat.

• Move into a warm room.
• For frostbite of an extremity (e.g., fingers, toes): Place the frostbitten part in very warm water. A bathtub or sink is often the quickest approach. The water should be very warm (104° to 108° F, or 40° to 42° C), but not hot enough to burn. Immersion in this warm water should continue until a pink flush signals the return of circulation to the frostbitten part (usually 30 minutes).
• For frostbite of the face (e.g., ears, nose): Apply warm wet washcloths to frostbitten area of the face. Continue doing this until a pink flush signals the return of circulation to the frostbitten area (usually 30 minutes).

Note: Do not rewarm a frostbitten area if there is a chance of refreezing.

FIRST AID Advice for Frostbite During Transport to a Medical Facility:

• Wrap frostbitten area in warm blanket or clean dressing.
• Protect frostbitten area from injury.
• Avoid walking on frozen feet if possible (Reason: may cause further tissue injury).

FIRST AID Advice for Hypothermia:

• Remove wet clothing.
• Wrap in warm blankets (or clothing, sleeping bag, even newspaper).
• Move into a warm space (e.g., home, building, car, tent).

WHEN TO CALL YOUR DOCTOR

HOME CARE ADVICE FOR MILD FROSTBITE

1. Reassurance: Frostbite means the nerves and skin are temporarily frozen. Most frostbite is mild and responds to warming up.
2. Rewarming - Rewarm the area rapidly with wet heat:  
   • Move into a warm room.
   • For Frostbite of an Extremity (e.g., fingers, toes): Place the frostbitten part in warm water. A bathtub or sink is often the quickest approach. The water should be very warm (104° to 108° F, or 40° to 42° C), but not hot enough to burn. Immersion in this warm water should continue until a pink flush signals the return of circulation to the frostbitten part (usually 30 minutes). At this point, the numbness should disappear.
   • For Frostbite of the Face (e.g., ears, nose): Apply warm wet washcloths to the frostbitten area of the face. Continue doing this until a pink flush signals the return of circulation to the frostbitten area (usually 30 minutes).
   • With more severe frostbite, the last 10 minutes of rewarming is usually painful.
   • If not using a tub, keep the rest of your child's body warm by covering with blankets.
3. Common Treatment Mistakes:
   • A common error is to apply snow to the frostbitten area or to massage it. Both can cause damage to thawing tissues.
   • Do not re-warm with dry heat, such as a heat lamp, heating pad or electric heater, because frostbitten skin cannot sense burning.
   • Do not re-warm if there is a high likelihood of refreezing in the next couple hours. Freezing-warming-freezing causes more damage than freezing-warming.
4. Drink Warm Liquids: Encourage warm liquids (e.g., hot chocolate).
5. Ibuprofen: For true frostbite, give ibuprofen for pain relief. (See Dosage table)
6. Aloe Vera Ointment: Apply aloe vera ointment to the area of frostbite twice daily for 5 days.
7. Prevention of Frostbite: (especially important in children with previous frostbite)
   • Cold sensitivity and recurrent frostbite is common following severe frostbite.
   • Dress in layers for cold weather. the first layer should be thermal underwear, and the outer layer needs to be waterproof. The layers should be loose, not tight. Mittens are warmer than gloves. Avoid tight gloves or shoes that might interfere with circulation.
   • Wear a hat, because over 50% of heat loss occurs from the head.
   • Change wet gloves or socks immediately.
   • Teach your child to recognize the earliest warnings of frostbite. Tell him that the tingling and numbness are signals from your body that you are not dressed adequately for the weather and that you need to go indoors.
8. Call Your Doctor If:
   • Color and sensation do not return to normal after 1 hour of re-warming
   • Frostbitten part develops blisters
   • Your child becomes worse

Disclaimer: This information is not intended be a substitute for professional medical advice. It is provided for educational purposes only. You assume full responsibility for how you choose to use this information.

Author and Senior Reviewer: Barton D. Schmitt, M.D.
Last Reviewed: 11/14/2011
Last Revised: 11/14/2011
Content Set: Pediatric HouseCalls Symptom Checker
Copyright 1994-2012 Barton D. Schmitt, M.D