STAY SAFE AS YOU SWIM
BE HYPOTHERMIA AWARE!
Hypothermia is a dangerous drop in the bodies essential core temperature below 35°C when the body loses heat faster than it can produce it, causing your heart, nervous system and other essential organs to not function properly.
Exposure to cold environments such as cold water, low air temperatures and wind chill can lead to the rapid onset of hypothermia. Whilst the colder the conditions the body is exposed to the more rapid the onset, factors such as age, gender, body type and acclimatization will influence how quickly you might develop hypothermia and its severity. There is therefore no reliable method of predicting the rate of onset in even the most seasoned swimmers.
When you are swimming in water colder than you, your body initiates a process to protect your vital organs. Blood vessels shunt (moving blood to where it's needed) the warm blood away from your skin and limbs towards your vital organs by reducing the blood flow to your extremities. This allows more oxygen to be delivered where it's needed the most. Your body will be working hard to maintain your core at its normal temperature. This process is called peripheral vasoconstriction. It's the body's way of protecting against hypothermia.
This process starts to reverse when you get out of the cold water. Your body begins to send the warm blood from the core back to the skin to warm up again. The problem is that it also cools the blood as it does so, as it's now mixing the warm blood with the cooler blood, and then re-circulates the cool blood back to the core, meaning that your temperature will drop further.
This is known as the 'after-drop'. This doesn't happen immediately, and when you exit the water you'll probably feel great for a short time. This delay occurs because your cooler blood hasn't reached your core straight away. Within a short space of time, however, you will begin to shiver. Shivering is one of our body's immediate reactions to generate heat. Shivering makes your muscles contract and relax quickly to produce heat to raise your body temperature.
The symptoms of hypothermia can onset at different rates and you may not always be aware of them developing as hypothermia can affect, amongst other things, your cognitive ability - ie. your ability to think clearly and make intelligent decisions. Your brain is very sensitive to the cold and electrical activity rapidly slows down in response to it, so your ability to make decisions and react becomes impaired.
Think you may be suffering from hypothermia?
If you suspect that either you or your swim buddy is suffering from the onset of hypothermia after exiting the water, that person should immediately dry off and wrap themselves in towels and layers of warm clothing and a hat, focusing particularly on the extremeties. A severely hypothermic swimmer may need medical attention so always inform a member of our staff immediately.
- Hunger and nausea
- Increased breathing
- Difficulty speaking
- Lack of coordination
- Increase in heart rate
- Poor judgement
- Cold, pale skin
- Numb hands and feet
- Shivering, but importantly, as hypothermia worsens, shivering stops
- Worsening coordination difficulties
- Slurred speech
- Significant confusion
- Apathy or lack of concern (doesn't recognise that they are in any danger)
- Weak pulse
- Shallow, slow breathing
- Paradox undressing - removes clothing despite the cold because they feel warm
- Muscles become stiff
- Slow pulse
- Loss of consciousness
- Shivering stops
- Extreme confusion
- A decline in consciousness
- Weak or irregular pulse
- Slow/shallow breathing
- Coma - can result in death