If frostbite is detected early, immediate action should be taken to restore circulation before permanent tissue damage occurs.

The affected area should be kept warm and gradually rewarmed.

Suitable methods include:

• Placing frozen hands beneath the armpits.
• Covering the affected ears, nose, or cheeks with warm cupped hands.
• Immersing the affected body part in warm water maintained at not more than 40°C.

Once the tissue has frozen, the affected area should never be rubbed or vigorously massaged, as this may cause additional damage to the frozen tissues. Gentle warming remains the safest and most effective treatment until professional medical care becomes available.

Non-Freezing Cold Injury (Immersion Foot)

Non-freezing cold injury, commonly known as Immersion Foot or Trench Foot, is a condition that occurs when the tissues of the feet or lower limbs remain exposed to cold, damp conditions for an extended period without actually freezing. Unlike frostbite, the affected tissues remain above the freezing point, but prolonged exposure to moisture and cold reduces blood circulation, resulting in tissue damage.

This condition is frequently experienced by survivors of shipwrecks who remain wet and motionless in lifeboats or liferafts for long periods. However, immersion foot may also occur in dry conditions when circulation to the feet is restricted. Additional contributing factors include wearing tight footwear, sitting in one position for prolonged periods with the feet hanging down, inadequate movement, and continuous exposure to cold weather.

Diagnosis

The early signs and symptoms of immersion foot include:

• The feet become pale or white in colour.
• Numbness and loss of normal sensation develop.
• The affected feet feel cold to the touch.
• Mild swelling of the feet may be present.

When the feet are gradually rewarmed, they usually become:

• Red and inflamed.
• Hot and swollen.
• Painful due to the return of blood circulation.

Prompt recognition of these symptoms is essential to prevent permanent tissue damage.

Prevention

Preventing immersion foot is extremely important for survivors spending long periods in survival craft.

The following preventive measures should be taken:

• Keep the feet as warm and dry as possible at all times.
• Loosen boot or shoe laces to improve blood circulation.
• Raise the feet whenever possible to reduce swelling.
• Perform toe and ankle exercises several times each day to maintain circulation.
• Remove footwear whenever practical and warm the feet by placing them beneath the armpits of another survivor while keeping them outside the clothing.
• If available, wrap spare clothing or blankets around the feet to provide additional insulation.
• Avoid smoking because it reduces blood circulation to the extremities and increases the risk of cold injury.

Treatment

Following rescue, the affected feet should not be rewarmed rapidly, as sudden warming may increase tissue damage.

The recommended treatment includes:

• Gradually warming the affected limbs.
• Avoiding any damage to the skin or rupture of existing blisters.
• Elevating the legs to reduce swelling.
• Covering the affected areas lightly with clean dressings or clothing.
• Seeking professional medical treatment as soon as possible.

Proper care during the recovery period helps reduce pain, prevents infection, and minimizes permanent damage to the affected tissues.