Overview
Hazardous heat exposure can occur indoors or outdoors and is dependent upon environmental factors, a person’s individual risk factors, and levels of physical exertion. Environmental factors contribute significantly to heat stress in Alabama, as normal summertime highs for west central Alabama are around 90° F. Heat is the leading cause of weather-related illness, injury, and fatality in the U.S.
Heat Illness
Heat illness ranges in severity from mild, such as a heat rash, to severe, in the case of heat stroke.
| Heat-Related Illness | Signs and Symptoms |
|---|---|
| Heat rash | •Clusters of red bumps on skin •Often appears on neck, upper chest, and skin folds |
| Heat syncope | •Fainting •Dizziness |
| Heat cramps | •Muscle spasms or pain •Usually occurs in legs, arms, or torso |
| Heat exhaustion | •Fatigue •Irritability •Thirst •Nausea and/or vomiting •Dizziness/lightheadedness •Heavy sweating •Elevated body temperature •Fast heart rate |
| Rhabdomyolysis | •Muscle pain •Dark urine or reduced urine output •Weakness |
| Heat stroke | •Confusion •Slurred speech •Unconsciousness •Seizures •Heavy sweating or hot, dry skin •Very high body temperature •Rapid heart rate |
NOTE:
One of the primary methods for regulating body temperature is by sweating. It is more difficult for this sweat to evaporate in humid environments, leading to an increase in the risk of heat illnesses like heat exhaustion or heat stroke.
Risk Factors for Heat Illness
Awareness of an increased likelihood of falling ill due to heat stress can help prevent the development of heat illness when paired with heat stress prevention measures. Heat-related illnesses are more prevalent in some individuals and scenarios than in others due to a variety of factors. These risk factors include:
- High temperature
- High humidity
- Direct sun exposure
- Indoor radiant heat sources
- Limited air movement
- Lack of acclimatization
- Dehydration
- Physical exertion
- Physical condition and health problems
- Certain medications
- Pregnancy
- Previous heat-related illness
- Obesity
- Diabetes
- High blood pressure
- Heart disease
- Lower levels of physical fitness
- Alcohol use
- Use of illicit drugs
Heat Illness Intervention
Heat Rash
- Move work to a cooler, less humid environment where possible.
- Keep the rash area dry.
Heat Cramps
- Move to a shaded area
- Loosen tight clothing
- Apply cool wet cloths
- Sip water or electrolyte drinks
If symptoms worsen, seek medical attention.
Heat Syncope
Fainting or dizziness- Move to a cool location
- Sit or lie down
- Slowly drink cool water, clear juice, or electrolyte drinks
If loss of consciousness occurs with heat syncope, seek medical attention.
Heat Exhaustion
- Move to a shaded area
- Loosen tight clothing
- Apply cool wet cloths
- Sip water or electrolyte drinks
If nausea or vomiting is severe, seek medical attention. If symptoms worsen, seek medical attention.
Rhabdomyolysis
Causes breakdown, rupture, and death of muscle tissue- Stop activity
- Drink cool liquids, preferably water
Seek immediate medical attention for suspected rhabdomyolysis.
Heat Stroke
- Move the individual to a cool and shaded location
- Call 911 or UAPD at 205-348-5454 IMMEDIATELY.
Heat Illness Prevention
Water. Rest. Shade.
Proper hydration is crucial to the prevention of heat illness. Cool potable water should be provided on all job sites taking place in hot environments, whether indoors or outdoors. Do not wait until thirsty to drink. For jobs in excess of two hours in a hot environment, electrolyte-containing drinks, such as sports drinks, should be accessible as water is not sufficient to replace loss of electrolytes through sweating. Substantial loss of electrolytes can lead to muscle cramps and other dangerous health problems.
CAUTION:
Not all cool liquids will keep you hydrated. Caffeinated drinks, sugary drinks, and alcohol all increase your likelihood of dehydration.
When heat stress is high, breaks should be required. The length and frequency of rest breaks should increase as heat stress rises. These breaks should last long enough for workers to adequately recover from the heat. These breaks should not be skipped and supervisors should ensure that all workers rest during recommended break periods. The duration of these breaks depends on multiple factors including:
- environmental heat
- physical activity level
- individual worker’s personal risk factors
The location of the breaks can shorten the duration required to recover. Cooler, shaded locations allow for a greater level of recovery in a shorter span of time. Examples of adequate outdoor locations include:
- shaded area
- air-conditioned vehicles
- nearby building/tent
- area with fans and/or misting devices
For indoor workers exposed to heat stress, workers should be moved away from heat sources like ovens and furnaces and into cool or air-conditioned areas for breaks.
Work Practices, Engineering Controls, and PPE
-
Acclimatization:
Gradually increase exposure to heat over 7-14 days:
New & Returning Workers – Start new workers and those returning from an absence at 20% of the workload. Increase the workload by 20% each day until they are performing a normal schedule.
Acclimatization can be maintained over weekends. Loss of the beneficial adaptations occurs when absences reach a week or more.
Acclimatization:
- Can be regained within 2-3 days.
- Is better maintained by those who are physically fit.
-
Monitoring & Supervision:
Heat conditions can change rapidly and people can become suddenly overcome by heat illness following a gradual decline.
An individual should be designated to monitor conditions and employees and to implement a heat illness prevention plan throughout the workday.
This individual must be properly trained on heat hazards.
Training should include:
- Identification and control of heat hazards
- Recognition of early symptoms of heat stress
- Administration of first aid for heat-related illness
-
Engineering Controls:
Where possible, engineering controls should be implemented as a first defense against heat hazards. The best options focus on reducing heat in the work environment and reducing manual workload with mechanization.
Engineering controls can include:
- Air conditioning
- Increased ventilation
- Cooling fans
- Local exhaust ventilation at points of high heat production or moisture
- Mechanical equipment to reduce manual workload (e.g., forklifts)
- Reflective shields to reduce radiant heat
-
Administrative Controls:
In work environments that cannot be cooled by engineering controls, utilize administrative controls to modify work activities to reduce the likelihood of heat stress.
Effective administrative controls for heat hazards include:
- Modification of work schedules so that the most strenuous activities are scheduled for earlier in the morning and/or later in the evening.
- Scheduling shorter shifts and spread work activities across more employees.
- Utilize pacing and require mandatory rest breaks in a cooler environment. The duration of the breaks should increase as heat stress rises.
- Ensure employees are drinking an adequate amount of water and/or electrolyte fluids.
- Implement a buddy system where workers observe one another for signs of heat illness.
-
Personal Protective Measures
Wherever possible, heat stress should be reduced by engineering and administrative controls. Personal protective measures/equipment should supplement those initiatives.
These supplemental measures can include:
- Clothing that is lightweight, loose-fitting and breathable
- Cooling neck wraps, hats, and/or vests
-
Emergency Preparedness
Identify certain elements of your plan BEFORE a heat advisory or an excessive heat warning is issued such as:
- Identifying your designated cool/shaded area for breaks
- Learning how to recognize and respond to heat illness
- Learning First Aid and CPR
During the implementation phase of heat stress emergency preparedness, ensure everyone on the job site knows:
- Rest breaks are mandatory
- The location of cool water/electrolyte-drinks
- Dialing 205-348-5454 for emergencies occurring on campus ensures faster response than dialing 911.
Resources
OSHA Heat Exposure First Aid
OSHA Heat Exposure Water Rest Shade
CDC Heat Stress
OSHA/NIOSH Heat Safety Tool
NIOSH Heat Stress Infographic
App from Apple and Google Play Stores featuring:
Current heat index and associated risk levels specific to geographic location
Hourly forecast of heat index values and risk levels
Signs/symptoms and first aid for heat-related illnesses.