Dangers of Excessive Heat
Lori Wright, Media Relations
In the month of July, UNH issued an Excessive Heat Alert four times,
which is a considerable amount considering in the previous two years,
only two alerts were issued.
curtailed operations in the winter, which apply to the entire campus
(except for emergency personnel) excessive heat alerts apply to
outdoor workers and staff who work in nonair-conditioned areas,
according to Brad Manning, director of environmental health and
Supervisors may consider relocation to an air-conditioned area if
available, staff may work from home if practical, or staff may simply
be released for the remainder of the day, according to Manning.
Supervisors are free and encouraged to send staff home with pay
if their work environment has reached intolerable and unhealthy
levels due to excessive heat. Staff will not be required to use
leave time/earned time in this instance.
“Each campus department that has staff working in non-air
conditioned areas should establish a heat alert procedure that can
be immediately activated when an alert is broadcast on the campus
email,” Manning said.
UNH monitors hot environments using the Wet Bulb Globe Temperature
(WBGT). The university also relies on national guidelines from the
American Conference of Governmental Industrial Hygienists that establish
threshold limit value for heat exposure using the WBGT.
While most staff may not have heard of these specific temperature
measurements, it is essential to gauging environmental conditions
because it measures air temperature, humidity in the air, radiant
heat and wind velocity.
“All four factors are crucial in determining the risk of heat
stress. The level of work activity, plus the clothes and the condition
of the employee, are additional factors that must be considered,”
“Heat stress” is the overall heat burden on the body
from the combination of the body heat generated while working, environmental
sources (air temperature, humidity, air movement, radiation from
the sun or hot surfaces/sources) and clothing.
“In outdoor occupations, summer sunshine is the main source
of heat. In nonair-conditioned indoor environments, high humidity
adds to the heat burden. In all instances, the cause of heat stress
is a working environment, which can potentially overwhelm the body's
ability to deal with heat,” Manning said.
Most people feel comfortable when the air temperature is between
68 and 80.6 degrees Fahrenheit (20°C and 27°C) and when
relative humidity ranges from 35 to 60 percent. “When air
temperature or humidity is higher, people feel uncomfortable. Such
situations do not cause harm as long as the body can adjust and
cope with the additional heat. Very hot environments can overwhelm
the body's coping mechanisms leading to a variety of serious and
possibly fatal conditions,” Manning said.
During times of high heat and humidity, employees who work outside
or in nonair-conditioned areas are susceptible to a number of heat
stress disorders, including heat exhaustion, heat stroke, heat cramps,
fainting and heat rash. Children and adolescents are more susceptible
to heat stress disorders, as are the elderly and adults who are
overweight or have high blood pressure.
“Many people confuse these disorders, but it is important
to be able to recognize each one and know what to do when it happens,”
Heat exhaustion occurs when someone sweats a lot and does
not drink enough fluids, take in enough salt or both. The simple
way to describe the worker is wet, white and weak. Signs and symptoms
are sweatiness; weak or tired, possibly giddy; nausea; normal or
slightly higher body temperature; and pale, clammy skin (sometimes
flushed). Someone who is experiencing heat exhaustion should rest
in a cool place, drink an electrolyte solution such as Gatorade
or another sports drink, and avoid caffeinated beverages such as
colas, iced tea or coffee. In severe cases involving vomiting or
fainting, call 911.
Heat stroke is the most serious health problem for people
working in the heat, but is not very common. It is caused by the
failure of the body to regulate its core temperature. Sweating stops
and the body cannot get rid of excess heat. Victims will die unless
they receive proper treatment promptly. Signs and symptoms include
mental confusion, delirium, fainting, or seizures; a body temperature
of 106ºF or higher; and hot, dry skin, usually red or bluish color.
If a person is experiencing heat stroke, call 911 immediately and
request an ambulance. Move the victim to a cool area, soak the victim
with cool water, and fan the victim vigorously to increase cooling.
Heat cramps are painful muscle spasms that occur when someone
drinks a lot of water, but does not replace salts lost from sweating.
Tired muscles – those used for performing the work –
are usually the most likely to have the cramps. Signs and symptoms
are cramping or spasms of muscles that may occur during or after
the work. To treat heat cramps, drink an electrolyte solution (sports
drink) such as Gatorade. If the cramps are severe or not relieved
by drinking a sports drink, seek medical attention.
Fainting usually happens to someone who is not used to working
in the hot environment and stands a lot. Moving around, rather than
standing still, will usually reduce the likelihood of fainting.
Signs and symptoms include a brief loss of consciousness; sweaty
skin, normal body temperature; and no signs of heat stroke or heat
exhaustion. In a fainting situation, the victim should lie down
in a cool place and seek medical attention if he or she has not
recovered after brief period of lying down.
Heat rash, also called prickly heat, may occur in hot and
humid environments where sweat cannot evaporate easily. When the
rash covers a large area or if it becomes infected, it may become
very uncomfortable. Heat rash may be prevented by resting in a cool
place and allowing the skin to dry. Signs and symptoms include a
rash characterized by small pink or red bumps; irritation or prickly
sensation; and itching. To combat heat rash, keep skin clean and
dry to prevent infection and wear loose cotton clothing. Cool baths
and air conditioning are very helpful, and some over-the counter
lotions may help ease pain and itching.