Wilderness Medicine Institute staff meeting heard
from noted thermophysiologist (a scientist who studies
human response to cold) Gordon Giesbrecht, Ph.D.
Dr. Giesbrecht teaches at the University of Manitoba
and combines well-published research with extensive
Arctic expedition experience, and a passion for educating
people on hypothermia, frostbite and cold weather
survival. Giesbrecht, who Outside magazine called “Dr.
a day in a cold injury workshop with WMI staff, and
then had the energy to give a public presentation
for the Lander community.
|Dr. Gordon Giesbrecht, also
known as "Dr. Popsicle"
Giesbrecht’s research and experience challenges
some common assumptions about hypothermia and cold
weather physiology. For example, many people believe
that if you fall into cold water, you are almost
immediately hypothermic. Not the case, says Giesbrecht,
who has measured the response to cold on himself.
He has lowered his body temperature to hypothermia
37 times during his research.
When we immerse ourselves in cold water, we immediately
gasp and breathe rapidly. Any of us who have accidentally
turned on the cold water in the shower knows the
response. But there is great danger if our head goes
underwater and we panic and inhale water. We might
drown. The key, according to Giesbrecht, is understanding
this response and controlling our breathing, as several
WMI Instructors experienced first-hand in the icy
Popo Agie River during the workshop. It’s important
to try to tread water slowly. Grab the edge of your
boat or the ice and keep your head above the water.
After a minute or two, your gasping should subside
and, as your skin becomes numb, the intensely uncomfortable
cold sensation should wane.
We have another 10 minutes before our muscles become
too cold to move effectively. We could use this time
to get out of the water, or to secure ourselves against
drowning. Giesbrecht gave examples of people who
have left on their wet clothing, letting it freeze
to the ice to prevent them from slipping beneath
the surface of the water. He also demonstrated how
to properly exit an icy pond or lake by rolling and
crawling to distribute your weight, rather than standing.
It’s another hour until our body temperature
drops far enough to make us critically hypothermic.
The scientist’s simple message is “1
minute, 10 minutes, 1 hour.” We need to control
our breathing and survive the first minute. Then
we have 10 minutes to move carefully and thoughtfully,
and an hour before we become gravely hypothermic.
Knowing this, while we still need to promptly treat
hypothermia, we don’t need to panic.
Addressing another myth, Giesbrecht noted that we
don’t lose most of our heat through our head
and neck. The head and neck are only 10 percent of
our body surface area and are no more efficient at
losing heat than the rest of our skin. This doesn’t
mean it’s not good advice to wear a hat, scarf
or hood when you are cold, just do so to insulate
exposed skin, not to support a myth about high heat
loss through our heads.
After we dunked WMI Instructors into the river,
we experimented with several ways to warm these volunteers.
We found that what we have been teaching—the
hypothermia wrap—is a sound field technique.
For this kind of situation, here are some ideas:
Place the shivering patient in dry sleeping bags
and wrap the bags with a plastic tarp to keep the
insulation dry and reduce heat loss. Hot sweet drinks
provide calories to fuel the shivering, which will
warm most patients.
Get wet clothing off the patient. There is a fear
that exposing wet cold people to the air when removing
their clothing will quickly cause their temperature
to drop. Giesbrecht commented that it takes a while
for people to become hypothermic. As long as we remove
wet clothing quickly and without jostling the cold
patient, they are better off with dry insulation.
We also explored placing the hypothermic patient
in the sleeping bag with a warm naked rescuer. This
isn’t much more effective than the simple hypothermia
wrap. A cold patient doesn’t absorb much heat
through their skin. The rescuer is really only a
source of heat to warm the sleeping bag and may be
more valuable on the surface—making camp and
hot drinks, cooking dinner, and making sure everyone
else on the expedition is safe and sound.
If you want to learn more about Dr. Giesbrecht’s