Dealing with the Effects of Cold

This leaflet is created from first aid advice provided by St John Ambulance, the nation's leading first aid charity. This advice is no substitute for first aid training - find a training course near you.


With frostbite the tissues of the extremities - usually the toes and the fingers - freeze due to low temperatures. In severe cases, it can lead to a permanent loss of sensation and, eventually, tissue death (gangrene) as the blood vessels become irreversibly damaged.

Frostbite usually occurs in freezing or windy and cold conditions. People who cannot move around are particularly susceptible. In many cases frostbite is accompanied by hypothermia and this should be treated accordingly.


There may be:

  • Pins and needles to begin with.
  • Pallor followed by numbness.
  • Hardening and stiffening of the skin.
  • A colour change to the skin of the affected area: first white, then mottled and blue.

On recovery, the skin may be red, hot, painful and blistered. Where gangrene occurs, the tissue may become black due to the loss of blood supply.


If possible move the person into the warmth before you thaw the affected part.

Gently remove rings, gloves and any other constrictions such as boots. Warm the affected part with your hands on your lap, or under the person's armpits. Rubbing the affected areas must be avoided, as this can damage the skin and other tissues.

Place the affected part in warm water at around 40°C (104°F). Dry carefully, and apply a light dressing of fluffed-up, dry gauze bandage.

Support and raise the affected limb to reduce swelling. An adult person may take two paracetamol tablets for intense pain. Take or send the person to hospital.


Do not:

  • Put the affected part near direct heat.
  • Attempt to thaw the affected part if there is a danger of it refreezing.
  • Allow the person to smoke.


Hypothermia develops when the body temperature falls below 35°C (95°F). The effects vary depending on the speed of the onset and the level to which the body temperature falls. Moderate hypothermia can usually be completely reversed.

Severe hypothermia - when the core body temperature falls below 30°C (86°F) - is often, but not always, fatal. However, no matter how low the body temperature is, it is always worth persisting with life-saving procedures until a doctor arrives to assess the person.


There may be:

  • Shivering, and pale, cold, dry skin.
  • Disorientation, apathy or irrational behaviour; occasionally, belligerence.
  • Impaired consciousness or lethargy.
  • Slow and shallow breathing.
  • Slow and weakening pulse.
  • In extreme cases the heart may stop.


  • For a person who has been brought in from outside, immediately replace wet clothing with warm, dry garments.
  • Put the person in a bed and ensure that they are well covered. Give them warm drinks or high-energy foods such as chocolate to help rewarm them.
  • Call 999/112 for emergency help. Monitor condition until help arrives.

Note: these hints are no substitute for thorough knowledge of first aid. St John Ambulance holds first aid courses throughout the country.

This leaflet was taken from the St John Ambulance website: frostbite and hypothermia. Copyright for this leaflet is with St John Ambulance.