Signs of Cold Water Shock
- Initial immersion responses – Cold shock response (0–3mins)
Immediately after immersion in cold water, rapid cooling of the skin causes a number of instinctive and reactions including gasping, hyperventilation, restriction of blood flows, and panic.
- Short term responses – Loss of performance (3–30mins)
Following the cold shock response, the hands, feet, arms and legs start to cool and blood flow continues to be restricted. This causes a decrease in muscle strength and endurance leading to muscle fatigue and reduced control over body movements. If the casualty is unable to get out of the water or use a buoyancy aid, this will ultimately result in drowning.
- Long term responses – Hypothermia (30mins+)
Over time, significant heat lost causes the core body temperature to drop leading to hypothermia.