Temperature extremes present serious hazards to the health, safety, and comfort of personnel involved in hazardous waste site operations. Both heat stress and cold exposure can impair judgment, reduce work efficiency, and lead to severe medical emergencies if not properly managed.
Site health and safety officers must consider these factors when:
- Selecting appropriate personal protective equipment (PPE)
- Determining work/rest schedules and mission durations
- Establishing standard operating procedures (SOPs) for site activities
- Conducting medical surveillance and monitoring programs
Heat Stress
Definition
Heat stress occurs when the body cannot adequately dissipate heat, leading to an increase in core body temperature. It can range from mild symptoms such as heat fatigue to severe conditions like heat stroke, which can be life-threatening.
Wearing PPE, especially impermeable suits, significantly increases the risk of heat stress by restricting the body’s ability to cool itself through sweating and air circulation.
Causes of Heat Stress
Heat stress develops from the interaction of several contributing factors:
- Environmental Conditions – High air temperature, humidity, radiant heat, and limited air movement.
- Clothing and PPE – Heavy or non-breathable protective suits reduce heat dissipation.
- Workload – High physical activity generates additional body heat.
- Worker Characteristics – Individual health, fitness, and hydration levels affect tolerance to heat.
Because heat stress is among the most common and potentially serious illnesses at hazardous waste sites, it requires ongoing monitoring, preventive measures, and prompt response to symptoms.
Personal Risk Factors
Individual susceptibility to heat stress varies widely. The following factors may increase a worker’s risk:
- Lack of physical fitness
- Lack of acclimatization to hot environments
- Age (older workers are at higher risk)
- Dehydration
- Obesity
- Alcohol or drug use
- Infections or fever
- Sunburn
- Diarrhea or other dehydration-related illnesses
- Chronic diseases (e.g., cardiovascular disorders)
Prevention and Monitoring
To protect workers from heat-related illnesses:
- Monitor environmental conditions and body temperature.
- Provide rest periods in shaded or cooled areas.
- Ensure adequate hydration before, during, and after shifts.
- Rotate personnel to limit exposure duration.
- Train employees to recognize symptoms of heat stress and report them immediately.