September 2011 - Iowa Pork Producers Association

‘It’s too damned hot for man or beast!’
By Kelley J. Donham MS, DVM, professor of Occupational and Environmental Health, director of Iowa’s
Center for Agricultural Safety and Health (I-CASH), University of Iowa
My pork producing dad used to say frequently, “It’s
too damned hot for man or beast.” This summer
has been no exception. My dad’s words rang in my
ears the first time many years ago, as I staggered
out of the haymow after stacking bales up under
the roof on a 100° F.-plus day. I was weak, dizzy,
confused and thirsty. My head hurt and I remember
I was so tired; I could hardly walk up the hill to the
house. After sitting down in the shade, drinking
about a gallon of sweet iced tea and consuming
three ham salad sandwiches, I started feeling better.
This was one of two times doing farm work that
I experienced these symptoms that I now know
was heat exhaustion (the first signs of the serious
condition heat stroke).
Later in life, as a practicing swine veterinarian, I
was called to a farm during another hot spell. I
walked into a 500-head-capacity building holding
40 lb. feeders – and found 500 pigs – all dead! The
ventilation had failed during the night and they
died of heat stroke.
Pigs and people are alike in many more ways than
just having the proclivity to eat until we are fat. We
are alike in that overheating can be deadly. However,
we have the advantage in that we sweat, an extremely
effective way to help keep us cool. As sweat
evaporates from our skin, it can remove nearly 2/3 of
the heat we generate when working. Pigs (like dogs
and cats) only sweat on their noses and foot pads,
not much help in cooling off. They have to rely on
panting, air movement and radiating their body heat
to a cool body (like a cement floor or water).
If you believe in global climate change (or not),
regardless, we are having and probably will have
more “too damned hot days.” We need to be prepared
to prevent the detrimental effects of heat for our own
health, the health of our family members, employees
and of course, the pigs. The basic take-home messages
follow and include: 1) the stages of heat illness and
symptoms in people; 2) prevention of heat illness in
people; 3) the concept of heat index; and 4) prevention
of heat illness in pigs.
Table 1: Stages of heat illness, symptoms and
prevention in people (from mild to severe)
• Heat cramps
• Dehydration with loss of salts from the body
• Weakness, muscle spasms, dizziness and
vomiting (often seen in football players in hot
weather)
• Cool off, drink water supplemented with salt,
or better yet, a balanced sports drink (e.g.,
Gatorade)
• Heat exhaustion
• Long work periods in hot environments,
dehydration and loss of body salts
• Extreme fatigue, thirst, headache, dizziness,
confusion and body temperature above normal
(greater than 38° C. or 100° F.)
• May lead to syncope (fainting) and heat stroke
if not attended to
• Prevention is taking more frequent breaks,
shade, maintaining hydration by drinking
at least 1.5 liters per hour (even if not thirsty),
and avoiding alcohol and tobacco. Wear
loose fitting “wicking” clothing that will allow
evaporation, such as polyester sport shirts
30 SEPTEMBER 2011