The following are the most usual symptoms and signs, but not all may be present.

  • Unexpected and unreasonable behaviour possibly accompanied by complaints of coldness and tiredness.
  • Physical and mental lethargy with failure to understand a question or orders.
  • Slurring of speech.
  • Violent outburst of unexpected energy and violent language, becoming uncooperative.
  • Failure of, or abnormality in, vision.
  • Twitching.
  • Lack of control of limbs, unsteadiness and complaining of numbness and cramp.
  • General shock with pallor and blueness of lips and nails.
  • Slow weak pulse, wheezing and coughing.
  • Try to reduce the chances of hypothermia by dressing to beat the cold. Wear layers of clothing and the outer layer should be wind and waterproof. A major source of heat loss is the head, wearing some sort of heat can help to reduce this loss.

When hypothermia is suspected the aim must be to prevent the casualty losing more body heat and to rewarm the casualty.