Chichester Yacht Club Magazine January 2018 | Page 14

Cold Water Shock for the ‘Man Overboard’
- by Tim Walker
We have all attended lectures and practical
sessions on ‘Man Overboard’ procedures,
which tend to concentrate on the actions
required to recover the casualty from the water
in a safe and timely manner. Perhaps it would
be a good idea to look at what is happening to
the person who is in the water? hypothermia, you
have done very well;
most die in the first
minute of
immersion". It is cold
water shock that tends to kill people around our
shores.
Recent research has identified the fact that
many people messing about in boats don't wear
their lifejackets because they think that falling in
the water is an occurrence that they could
relatively easily get through because they
believe themselves to be strong swimmers, or
that their crew will rapidly get them from the
water. What is cold water shock?
The effect on the body of entering water 15°C
and below is often underestimated. This shock
can be the precursor to drowning.
Cold Water Shock is a leading cause of death
that many people fail to appreciate. Many
deaths recorded by coroners are mistakenly
attributed to either hypothermia, or drowning,
when in fact the cause of death, or cause
leading up to the death, is something different.
One of the authors of the seminal work
"Essentials of Sea Survival", Professor Mike
Tipton, is quoted as saying "if you are lucky
enough to survive long enough to die of
It is the body's short term involuntary response
to being suddenly immersed in cold water. The
waters around the UK are officially cold (10-
15°) and when the body enters this cold
environment there are a number of
physiological responses. The sudden lowering
of skin temperature is one of the most profound
stimuli that the body can encounter. The
responses tend to be short lived, but threaten
survival.
What's the risk?
Anything below 15°C is defined as cold water
and can seriously affect your breathing and
movement, so the risk in UK, Ireland and
Northern European waters is significant most of
the year as the average temperature is 12°C.
What happens to you?
Cold water shock causes the blood
vessels in the skin to close, which
increases the resistance of blood flow.
Heart rate is also increased. As a result
the heart has to work harder and your
blood pressure goes up. Cold water
shock can therefore cause heart
attacks, even in the relatively young and
healthy.
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