On May 27, 2017, 25-year old Rachel Daly collapsed during a soccer match as temperatures climbed into the 90s. She was taken by ambulance to the hospital and treated for heat illness. A 25-year old athlete with temperatures barely reaching into the 90’s, Rachel says this was a "frightening experience."
Now consider that our workforce is middle aged, out of shape, some with a poor diet or night of drinking alcohol prior to starting a work shift and we have what I call Double Trouble.
Not only do heat emergencies cause hypovolemia (loss of fluid), but loss of blood chemistry (electrolytes). Add a worker with just about any illness or significant aging and you have your recipe for potential disaster, yet we tend to treat heat related illness as if it is no big deal.
OSHA investigated 25 incidents of heat-related illness in 2005. In almost half of the cases, the worker involved was on their first day of work and in 80 percent of the cases the worker involved had only been on the job for four or fewer days. It is easy to understand that employees need to acclimatize to the heat.
Risk of heat-emergencies becomes greater as workers are exposed to hot and humid conditions. While OSHA does not have a specific standard (rule) for heat-emergencies, it is covered by the general rule of keeping employees healthy and safe. OSHA list there are five types of heat illness, but the last three could be classified as potential emergencies — (1) heat rash, (2) heat fatigue, (3) heat cramps, (4) heat exhaustion, and (5) heat stroke.
Heat Rash is the most common problem in hot work environments where the skin is persistently wetted by unevaporated sweat. Prickly heat is manifested as red papules and usually appears in areas where the clothing is restrictive. As sweating increases, these papules give rise to a prickling sensation. Heat rash papules may become infected if they are not treated. In most cases, heat rashes will disappear when the affected individual returns to a cool environment.
Home remedies for treating heat rash include washing the affected area with a mild soap and rinsing the area, then gently drying the area. Wear clothing that allows the skin to breathe in a hot environment. Stay hydrated. Drink plenty of water to prevent dehydration in hot environments.
Heat Fatigue is often caused by a lack of acclimatization. A program of acclimatization and training for work in hot environments is advisable. The signs and symptoms of heat fatigue include impaired performance of skilled manual, mental, or vigilance jobs. There is no treatment for heat fatigue except to remove the heat stress before a more serious heat-related condition develops.
Heat cramps usually happen first when you’ve been physically active in the heat. They can also occur with non-activity depending on heat and humidity. They are especially likely in the elderly or small children and overweight people.
These risk factors are due to difficulty regulating the internal body temperature. Heat cramps is muscle pain and tightness.If you or someone you know is experiencing heat cramps, you should:
- Move to a cooler area, out of direct sunlight.
- Gently massage the cramping muscle.
- Stretch the muscle gently.
- Drink cool water or sports drinks
Symptoms of heat exhaustion include:
- Pale skin
- Heavy sweating
- Muscle cramps
- Mild confusion
- Extreme thirst
- Nausea or vomiting
- Fast heart rate or breathing
To treat heat exhaustion, you should:
- Move to a cooler area, out of direct sunlight
- Loosen clothing
- Apply cool, wet towels to your face, neck, chest, and limbs
- Have someone fan your skin
- Drink cool water or sports drinks, but don’t drink too quickly
With heatstroke, the above symptoms of heat exhaustion may be present, plus:
- Neurological issues such as confusion, irritability, loss of concentration
- Rapid, shallow breathing
- Rapid, weak pulse
- Body temperature 104°F or above
- Irrational behavior or hallucinations
- Loss of consciousness
- Dry skin
Sweating may be present in heatstroke. However, a person who is experiencing heatstroke may have wet clothes from previous sweating, but now have warm dry skin from dehydration.Heatstroke is a life-threatening emergency. Call 911 or go to an emergency room immediately. In the meantime:
- Move the person to a cooler area or shade
- Loosen clothing, but remove any sweaty clothing
- Apply cool, wet towels to the face, neck, chest, and limbs
- Apply ice, if you have it, to the armpits, wrists, and groin (this cools down the circulating blood supply which helps cool the body)
- Offer cool water or sports drinks but only if the person is conscious
If you feel like you are not able to manage a heat related emergency do the following:
- Call 911 or go to the emergency room if vomiting, seizures, or unconsciousness
- Don’t give the person anything to drink if they’re vomiting or unconscious
- Never offer a drink containing alcohol or caffeine to someone experiencing a heat emergency
Firefighters are prone to having heat related illness due to heavy gear, exposure to sun and by dancing with the red devil. We rotate our work, rehab and must be checked by a medic prior to re-entry into hot zones.
This planned management of heat stress and illness is not just hope and pray effort. It is a well-planned event where we actually expect to have heat illness, with the goal of preventing the emergency.
The best way to manage these emergencies is with prevention. Stay in the shade or in well ventilated, air-conditioned areas during the hottest part of the day. Acclimatize workers by exposing them to work in hot environments for progressively longer periods.
NIOSH (1986) suggests that workers who have had previous experience in jobs where heat levels are high enough to produce heat stress may acclimatize with a regimen of 50 percent exposure on day one, 60% on day two, 80% on day three, and 100% on day four. For new workers who will be similarly exposed, the regimen should be 20% on day one, with a 20% increase in exposure each additional day.
Heat conduction blocking methods include insulating the hot surface that generates the heat and changing the surface itself. Simple devices such as shields, can be used to reduce radiant heat, i.e. heat coming from hot surfaces within the worker’s line of sight.
Polished surfaces make the best barriers, although special glass or metal mesh surfaces can be used if visibility is a problem With some sources of radiation, such as heating pipes, it is possible to use both insulation and surface modifications to achieve a substantial reduction in radiant heat.
Other precautions involve rescheduling hot jobs or rotating personnel in and out of heated work, providing rest and cool down time regularly and consistently. Wearing light-colored and loose or reflective clothing, auxiliary body cooling ice vest and other water cooled garments. Drinking plenty of fluids is a primary prevention and of course avoiding alcohol.
Remember, as the temperature and relative humidity increases, the chances of heat emergencies go up. The high humidity causes sweat to lay on the skin instead of evaporating. This sweats acts as a blanket, causing rapid temperature rise, short circuiting the thermostat in the brain, causing heat stroke.
Monitoring workers who are at risk of heat stress, such as those wearing semi-permeable or impermeable clothing when the temperature exceeds 70°F, while working at high metabolic loads (greater than 500 kcal/hour).
- Personal monitoring can be done by checking the heart rate, recovery heart rate, oral temperature, or extent of body water loss.
- To check the heart rate, count pulse for 30 seconds at the beginning of the rest period. If the heart rate exceeds 110 beats per minute, shorten the next work period by one third and maintain the same rest period.
- The recovery heart rate can be checked by comparing the pulse rate taken at 30 seconds (P1) with the pulse rate taken at 2.5 minutes (P3) after the rest break starts. The two pulse rates can be interpreted using the following criteria.
- Check oral temperature with a clinical thermometer after work but before the employee drinks water. If the oral temperature taken under the tongue exceeds 37.6°C (99.6°F), shorten the next work cycle by one third.
- Measure body water loss by weighing the worker on a scale at the beginning and end of each work day. The worker’s weight loss should not exceed 1.5 percent of total body weight in a work day. If a weight loss exceeding this amount is observed, fluid intake should increase.
Heat Stress Training Program
OSHA recommends that companies develop a heat stress training program, and incorporate into health and safety plans at least the following components:
- Knowledge of the hazards of heat stress;
- Recognition of predisposing factors, danger signs, and symptoms;
- Awareness of first-aid procedures for, and the potential health effects of, heat stroke;
- Employee responsibilities in avoiding heat stress;
- Dangers of using drugs, including therapeutic ones, and alcohol in hot work environments;
- Use of protective clothing and equipment; and
- Purpose and coverage of environmental and medical surveillance programs and the advantages of worker participation in such programs.