Abstract: On July 20, 2005, an employee, a laborer, was employed by Guy Yocom Construction Ltd. He suffered a heat stroke while performing housekeeping activities. The morning of the event, the ambient temperature was between 97 and 107 degrees Fahrenheit, the wind speed was as low as 6 mph, and relative humidity was as high as 65 percent. The day of the event was the employee's first day at this site. The two days prior to that, employee worked in San Juan Capistrano, a much cooler location. As a result, acclimatization appears to be a factor in this illness. The employee was transported to Eisenhower Medical Center in Rancho Mirage, 4.5 miles away. The employee was diagnosed with exertional heat stroke. He was hospitalized and treated from heat stroke.