Working in Hot Conditions

With the heat of summer here, supervisors and employees need to plan ahead to keep workers safe.

And heat is more than a discomfort. It is becoming more dangerous as nine of the last 10 years were among the warmest on record. According to Bureau of Labor Statistics, 387 workers lost their lives from 2013 to 2022 due to exposure to environmental heat and thousands more are sickened. 

Most outdoor deaths, 50 percent to 70 percent, occur in the first few days of working in warm or hot environments because the body needs to build a tolerance to the heat gradually over time, according to the Occupational Health and Safety Administration (OSHA). The process of building tolerance is called heat acclimatization.

Health becomes at risk in warm to hot environments, especially when someone is physically active. The human body relies on its ability to get rid of excess heat by sweating and increasing blood flow to the skin.

If heat dissipation does not happen quickly enough, the internal body temperature keeps rising and the worker may experience symptoms that include thirst, irritability, a rash, cramping, heat exhaustion, or heat stroke, which is the most severe heat-related illness. Workers suffering from heat stroke experience mental dysfunction such as unconsciousness, confusion, disorientation, or slurred speech.

Have a plan

At a minimum, employers should provide adequate water, rest breaks, and shade or a cool rest area for employees. OSHA advises that supervisors should have a plan ready to implement on the job site and know how to assess the combination of temperature, humidity, air flow and radiant heat from sunlight or nearby heat sources. To help in planning, physical workload can be estimated using OSHA tables. In addition to using a thermometer to assess conditions in the workplace, employers should also be aware of whether workers’ clothing increases risk. Layering clothing is not advised and fabrics should be considered. Materials that limit vapor permeability and airflow are not advised.

A worker’s body size and build should also be taken consideration, with obesity being among factors. Guidelines are also available through OSHA that offer specific information on safety guidelines.

Legal implications can also arise if a death or injury happens in hot conditions, though they can be hard to assess.

The trade association Plumbing Heating Cooling Contractors (PHCC) “does not have guidance for working in elevated temperature conditions other than advising contractors to follow OSHA safety guidelines and make common sense decisions for the safety of their workforce. In these days of workforce shortages, PHCC contractors work to protect the most valued of the business’s assets, their workers, says Chuck White, vice president of regulatory affairs. “Unfortunately, accidents may happen even when the best prepared safety plans are in place, the results of any injury or accident are always tragic and regrettable. Any type of incident brings the possibility of legal action with the expenses related thereto, but the sense of grief or loss to the contractor might never be assuaged by writing a check.”

What to think about

Here is a list of points from OSHA to shape a prevention plan:

• Who will provide oversight on a daily basis?
• How will new workers gradually develop heat tolerance?
• Temporary workers may be more susceptible to heat and require closer supervision.
• Workers returning from extended leave (typically defined as more than two weeks) may also be at increased risk.
• How will the employer ensure that first aid is adequate and the protocol for summoning medical assistance in situations beyond first-aid is effective?
• What engineering controls and work practices will be used to reduce heat stress?
• How will heat stress be measured?
• How to respond when the National Weather Service issues a heat advisory or heat warning?
• How will we determine if the total heat stress is hazardous?
• What training will be provided to workers and supervisors?