Irish Sea Kayaking Association
to protect their lungs in the following hours. There are two circumstances which may re-
violently, this time indicating that core body temperature is under threat. Shivering, ie rapid
duce ones chances of drowning; one is a
contractions of antagonistic muscles burns en-
primitive physiological reflex called the “Diving
ergy to create internal heat. (About 80% of all
response� and the second is an observed
energy we consume goes toward heat genera-
rapid cooling in very cold water which reduces brain metabolism and thus may improve sur-
tion rather than movement.) The intensity of shivering is diminished in people with a low
vivability. I wouldn't hang my hat on either of
blood sugar- such as those who have had a
those responses getting you out of trouble.
long day of paddling already completed. It may not even occur at all in such circumstances. A
Long Term Responses.
similar situation arises after alcohol consumption where the liver struggles to maintain sugar
Here we finally discuss hypothermia. Hope-
levels. Shivering may fail to occur and such
fully, the winter kayaker will have been suitably
persons may perceive less discomfort from the
attired- dry/ wet suited, head cover, pfd, hand
cold. When temperature of the body falls be-
and feet cover. In spite of the great capacity of cold water to extract heat from the warm body,
low 30 degrees, shivering will cease as muscles become spastic. The body withdraws into
hypothermia is unlikely to kill within thirty min-
a foetal like position. Skin colour is not a reli-
utes of immersion for a fit clothed head-out-of-
able indicator of hypothermia. While initially
water adult even in water as cold as 5 de-
pale, blood vessel muscles may paralyse then
grees. It is appropriate to acknowledge here that some of our knowledge of hypothermia
relax allowing highly oxygenated blood into the skin, causing a red-brick colour. As hypother-
derives from the notorious experiments carried
mia progresses cerebral activity diminishes.
out on Concentration Camp prisoners in Da-
Consciousness is lost around core tempera-
chau by the Nazis. Overtly, the hypothermia
ture of 30 degrees. Keeping the unconscious
victim is shivering and if conscious, speech is slurred. They tend to be uncoordinated, un-
victim's airway clear of water is obviously paramount. Below 28 degrees, the heart may
communicative and introverted and show a
spontaneously arrest. Arrest during thus stage
general slowing of physical and mental activity.
can result from rough handling so handle the
It can increase errors of judgement, reduced
victim with care. With respect to kayaking, the
perception, poor leadership and dropping vital equipment. In profound hypothermia, the pa-
presence or absence of shivering or discolouration of the skin should not be regarded as a
tient will be unconscious and unresponsive to
reliable indicator of hypothermia.
painful stimuli. Shivering is an unreliable sign. It can occur immediately on immersion due to
Body cooling during water immersion can oc-
various physiological responses and in that instance, does not indicate a lowered core
cur five times more quickly than it does in air of the same temperatures. In no circumstances
temperature. It will usually resolve as skin
are you better off in water than out of it so re-
temperature falls to match that of the water.
maining in or at least on the kayak even if up-
With continued immersion lasting around fif-
turned and draped across is better than re-
teen minutes, shivering resumes from intermittent initially to continuous, sometimes quite
maining in the water.
18!