Abstract: Employee #1 and two coworkers, of Cardinal Contracting, Inc., were on their fourth day of welding and shallow excavation work at a natural gas plant. They had finished the outside welding early in the afternoon and headed back to the maintenance shop and break room. After over an hour in the shade on break, Employee #1 complained of a bad feeling and a fluttering heart. He went into the break room, sat at a table, and then suddenly collapsed. Responding coworkers, suspecting heat stroke, and treated him with ice and administered CPR until medical help arrived. Employee #1 was flown by helicopter to a local hospital, where he was pronounced dead. Subsequent investigation determined that Cardinal had met its responsibilities with respect to the hazards of heat stress by informing employees of the symptoms, protective measures, and treatment, and also by providing them with suitable supplies, equipment, and facilities. A large sun umbrella had been used to shade the welders where they were working. They took frequent water breaks using a cooler available on their truck, and they were allowed to take breaks whenever necessary, with air-conditioned rooms available. They carried two-way radios to alert others of emergencies. The plant's site manager was also well prepared; all the company's employees knew how to perform CPR and how to contact outside medical personnel.