Case Studies

The following heat-related case studies are the result of from OSHA enforcement investigations. Some identifying details have been changed to protect the privacy of workers and employers.

Case #1: Roofing worker

In July, a 42-year-old man started a new job as a roofer. His employer did not have a formal plan to protect new workers from heat-related illness although there was plentiful water, ice, and Gatorade available at the site. The worker felt fine during his first two days of work. His third day on the job was slightly warmer, with a high temperature of about 86°F and relative humidity of 57%, for a heat index of 90°F. In the afternoon, the worker told his co-workers he felt hot and sick. He climbed down from the roof and went to sit by himself in the sun. When his co-workers checked on him a few minutes later, he had symptoms of heat stroke. He was taken to a hospital where he died. Scattered clouds may have reduced the radiant temperature somewhat but reconstruction showed a wet-bulb globe temperature of 82°F based on data from a nearby airport.

Lessons to learn from this case:

• Protect new workers during their first two weeks on the job. Make sure they take plenty of rest breaks and drink enough fluids.
• Never leave workers alone when they complain of heat-related symptoms. Their condition can worsen quickly! Take them to a cool location and provide first aid. Even a brief delay in first aid can make the difference between life and death.
• Temperatures do not have to be extremely hot to cause heat stroke in workers. Remember, total heat stress is a combination of environmental heat and workload. Air temperatures in the 80s (°F) are high enough to result in a Heat Index value of 90°F. They are also high enough to kill some workers.

Case #2: Delivery worker

A 50-year-old man had been working at a delivery company for six years. His job involved driving a vehicle and walking in residential neighborhoods to deliver mail and packages. In late May, the weather suddenly became hotter. On the second day of hot weather, this worker developed heat cramps and heat exhaustion. He was hospitalized for two days with acute kidney failure due to dehydration. His condition improved after intravenous fluid replacement.

Lessons to learn from this case:

• Even experienced workers are vulnerable to heat-related illness when the weather becomes warmer. Throughout the first week of warmer conditions, treat all workers as if they need to adapt to working in the heat. Take extra precautions to protect them from heat-related illnesses.
• Make sure workers drink enough fluids during warm or hot weather.

Case #3: Foundry worker

A 35-year-old employee had worked at a foundry for six years. The indoor workplace had high levels of environmental heat from ovens and molten metal. His normal job tasks were in a cooler area of the building. On the day of the incident, he was asked to perform a job in a hotter environment near an oven. He wore heavy protective clothing to prevent skin burns. After several hours of work, the man collapsed and died of heat stroke.

Lessons to learn from this case:

• Heat-related illness can occur indoors. The risk is not limited to outdoor workers.
• Some types of work clothing prevent the release of heat from the body. Environmental heat measurements underestimate the risk of heat-related illness in these situations.
• Workers are at risk of heat-related illness when they are reassigned to warmer job tasks.

More OSHA Cases

Review a list of heat-related fatalities and catastrophes investigated by OSHA.