Thanks to Susan
Haddock, University of Florida/IFAS Extension, Commercial Horticulture and
Integrated Pest Management, Hillsborough County, for this installment of
“Personal Rootzone” from the July issue of SportsTurf:
can be a major concern for outdoor workers, especially during the summer
months. Heat stress can result in heat stroke, heat exhaustion, heat cramps, or
heat rashes. Heat rash and cramps are the mildest forms of heat stress. Heat
exhaustion can occur when workers are exposed to high temperatures, especially
when combined with high humidity and strenuous activity. Without treatment,
heat exhaustion can lead to life-threatening heat stroke. Workers can also be
at greater risk of injuries due to sweaty palms, fogged-up safety glasses, and
dizziness. Learn how to identify the symptoms and protect yourself and workers
from heat stress.
is the buildup in the body of heat generated by the muscles during work, and
from heat coming from the hot work environment. When the body is overheated
less blood flows to the brain, muscles, and other organs. Because there is no
pain, workers may not realize when they become weak and tired, and that they
are less alert and less able to use good judgment. An increase in body temperature
of 2 degrees F can affect mental performance and an increase in 5 degrees F can
cause serious illness or death.
Signs and symptoms
Cool moist skin with goose bumps in
Dry mouth, dry membranes
No spit present
Weak rapid pulse (slow if person has
Central nervous system depression
Loss of coordination
managers prevent worker heat stress concerns?
Assign a supervisor for heat stress
Train workers and supervisors in the
prevention, recognition, and treatment of heat stress, and conduct safety
meetings during heat spells.
Acclimate workers when they begin to
work under hot conditions by assigning lighter workdays, longer rest periods,
and watching workers’ response for 5-7 days.
Account for the conditions of work
by checking weather conditions, how heavy the work is, and if the worker has to
wear additional protective wear and equipment.
Account for the conditions of the
workers by knowing if the worker has been sick, is rested, taking medications,
or has consumed alcohol.
Manage work activities by setting up
work breaks, rotating strenuous tasks, scheduling heavy work for cooler hours,
and postponing non-essential tasks during heat spells.
Establish a drinking water program.
Provide additional measures such as
special cooling and breathable clothing, prove shade, use air-conditioned
mobile equipment, and modify pesticide usage to reduce the need for personal
protective equipment (PPE).
Recognize that pesticide poisoning
has similar, but some different, signs and symptoms such as moist membranes,
salivation, tears, spit, slow pulse, nausea and diarrhea, possible small
pupils, and coma. There can also be combined effects of heat stress and
Take action and provide first aid if
workers show signs and symptoms of heat stress.
recommendations for workers are to drink at least one cup of water every 30
minutes and greater amounts as heat conditions become more extreme and workload
level is more strenuous, even if they are not thirsty. Drinking two or three
cups of water before work provides a head start, and they should continue
drinking water into the evening to replace all water lost through sweating.
During extreme heat or when wearing confining PPE, workers should be advised to
drink a pint or more of water before beginning work. Managers should be aware
of workers who have fluid retention or other medical problems that may affect
the worker’s intake of fluids. Also, managers should be aware of workers who,
due to economic pressure or toilet availability, tend to limit the amount of
water they drink or needed breaks.
Setting rest periods
Work and rest
periods need to consider workload levels, air temperature, humidity, sunlight
conditions, and worker clothing and PPE. Workers will recover better from heat
with shorter, more frequent breaks than longer, less frequent breaks. For
heavier work in higher temperatures and higher humidity, longer more frequent
breaks are needed. If possible, breaks should be taken in a shaded or air
conditioned area. In general, if performing heavy work at 95 degrees F with 30%
humidity, each hour of work should include a 15-minute break. Break times need
to increase and work times need to decrease significantly as temperature and
humidity increase. When air temperatures reach 105 degrees F, each hour of work
should include a 45-minute break.
For more information on heat stress, and setting work/rest periods and minimum water to drink, see this.