When exposed to the cold for too long, your body loses its ability to generate enough heat, and the core temperature starts to drop. Symptoms of mild hypothermia aren’t always obvious, and are often initially picked up by observers. It is important to be aware of the symptoms of hypothermia and know when it is necessary to abort the swim.
Stages of Hypothermia:
Hypothermia is often defined as any body temperature below 35.0°C. It is further classified into stages of severity based on core temperature.
Mild Hypothermia (32-35°C)
Moderate Hypothermia (28-32°C)
Severe Hypothermia (below 28°C)
Shivering is most likely the first thing you will notice as this is your body's automatic attempt to warm itself. Other symptoms of mild hypothermia include shallow breathing, exhaustion, lack of muscle coordination and slight confusion or foggy thoughts.
As your body temperature drops even further, you may start to feel drowsy, clumsy and confused. When core temperature drops below 32°C, shivering stops, at which point medical help is required (you do not want to reach this stage!)
During your cold water swim, it is important to perform regular “self checks” to ensure you’re not in danger. Most importantly, always have somebody observing you, or buddy up with another swimmer or small group of swimmers.
Can I open and close my hands?
Am I swimming in a straight line?
Am I thinking clearly? (e.g. Ask yourself what day of the week it is.)
I'm not shivering
If the answer is yes to all of these, you should be fine to carry on, unless instructed otherwise by your observer. Remember - safety first!