Heat cramps (Miners’ cramps)

The stokers who worked in the steamers of the past were well acquainted with heat cramps. This condition arises mainly in individuals with good physical condition when they are exposed to sudden and strong physical strain and sweat a lot (For example during a football match ashore)

The temperature of the air may be normal. The cramps may occur in all muscles of the body, but particularly in the legs. The condition is harmless if the patient is brought to a cool place and is given salt containing drinks.


Heat collapse

Heat collapse is the most common of the conditions induced by heat. It develops on the ground of loss of water and salt combined with a malfunction of the heat regulatory mechanism, most often following physical activity.

The first symptoms are malaise, vertigo, headache and anorexia sometimes followed by loss of consciousness. The skin is greyish pale, cold and damp. The pupils are dilated, the blood pressure often reduced. The body temperature is usually normal, but may be slightly less than normal.

A person with heat collapse should be moved to a cool place. He should be positioned with his upper body elevated and be given salt containing beverages.

Heat stroke

Heat stroke is the most serious of the conditions caused by heat, and may be fatal. It is most often seen in individuals suffering from chronic diseases. In the maritime industry heat stroke has been observed in persons with alcohol and drug problems. The condition may occur when the air temperature is high, especially when the relative humidity in the air is also high. Direct sun exposure is not a prerequisite. Most cases occur indoors.

The cause of heat stroke is a complete breakdown of the heat regulatory system. Early recognition is important, albeit sometimes difficult. The cardinal signs are severe hyperthermia (T > 41 C), cessation of sweating, and mental disturbances. The patient may complain of headache, malaise and vertigo. He gives an impression of fever and exhaustion and may faint. A body temperature in excess of 42 C signals great danger. The condition requires rapid and intensive action. Loss of time must be avoided. Medical evacuation is indicated when possible.



  • undress the victim and move him to a cool place with circulation of fresh and cold air. Fans are useful. Oxygen may help
  • insert a large gauge intravenous catheter
  • in case of convulsions, administer 5 mg of diazepam intramuscularly
  • start infusion of physiological saline solution or Ringer’s solution (a bolus of 2 litres over the first hour and an additional one litre per hour for the next 3 hours) Be aware of possible lung oedema.
  • monitor blood pressure
  • as soon as possible flush the patient with large amounts of cold water from any source, or submerge the patient in ice cold water. Measure the body temperature every 10 minutes. When the temperature has fallen below 39.5 degrees C, the patient may leave the water.
  • continue rinsing with a sponge and cold water, or place rubber gloves filled with ice cubes in the arm pits and groins
  • the patient should remain in a cold place until all symptoms have subsided