University of Otago Associate Prof Chris Button is
researching links between the shock of falling into cold
water, and drowning. Photo by Peter McIntosh.
Many drowning deaths can be prevented if people who fall
into cold water keep calm and let the body's initial shock
response wear off, ''dramatic'' new University of Otago
Associate Prof Chris Button, of the Otago School of Physical
Education, Sport and Exercise Sciences, and his colleagues
have been testing the body's response to sudden cold water
immersion, with support from Water Safety New Zealand.
And ''incredible'' results had been achieved, after study
participants were plunged into 10degC water in the school's
flume (pool), he said.
They recovered from the cold shock response in two to three
And researchers also found, that with repetition and basic
mental training, the duration and intensity of this ''shock
response'' could be halved.
After a week or so of repeated immersions, combined with
mental skills training, and basic suggestions to improve
treading water technique, the participants were ''much calmer
in the cold water''.
This behaviour change ''blew me away'', he said.
The research findings could help ''dramatically reduce New
Zealand's horrific drowning rates'', and also applied even
when water was considerably colder.
Drowning is New Zealand's third highest cause of
unintentional death, and there were 81 drowning-related
deaths last year. Most drownings were thought to occur in the
first few minutes after falling into the water. The body's
''shock response'' was to blame, he said.
An early ''gasp response'' was followed by rapid
And often when people gasped, they also breathed water into
their lungs and drowned, he said.
In the South, holidays were often spent beside icy lakes,
rivers and the sea.
And people fell into rivers, from capsizing boats, or were
swept off rocks while fishing.
It was ''absolutely critical'' that, instead of panicking,
people who had fallen into the water should ''take a
moment'', knowing that after two or three minutes they would
be able to ''breathe more smoothly'', he advised.
After their bodies had adjusted to the cold, people should
also avoid taking a ''bad decision'' and decide their best
plan for survival.
Prof Button and Water Safety New Zealand have compiled a list
of survival tips, which include remaining calm; holding the
breath for the first five to seven seconds, if possible,
after immersion, to avoid gasping; and floating initially,
before deciding on the best survival plan.
Trying to swim while still affected by initial cold shock was
''probably the worst thing you could do'', Prof Button said.
Water Safety New Zealand chief executive Matt Claridge said
the Otago findings were important and, combined with other
efforts, could help cut the country's drowning toll.