The dog days of summer are upon us, but what does that actually mean? This phrase refers to the hottest, most uncomfortable part of the summer, usually ranging from July through August. In ancient times, the return of Sirius (the Dog Star), which is the brightest star in the night sky, would be a forerunner of the hottest phase of the summer. For many, the month of August may mean the end of summer vacation is approaching, but for outdoor workers, these dog days mean dangerously hot temperatures. Extreme heat causes more deaths than any other weather-related hazard; each year more than 65,000 people seek medical treatment for extreme heat exposure. According to OSHA, in 2014 there were 2,630 workers who suffered from heat-related illness, and 18 died from heat stroke and related causes on the job. Heat-related illnesses are not the only concern; work-related exposure to heat can also result in reduced productivity and growing risk of injuries, such as those caused by sweaty palms, fogged-up safety glasses, and cognitive impairment.
Last year, NIOSH published Criteria for a Recommended Standard: Occupational Exposure to Heat and Hot Environments. This technical document provides safety professionals and employers an evaluation of the scientific data on heat stress and NIOSH recommendations. This summer, NIOSH and OSHA released a redesigned OSHA-NIOSH Heat Safety Tool app. The app uses the device’s geolocation capabilities to pull temperature and humidity data from National Oceanic and Atmospheric Administration satellites to determine the heat index. The app shows the current risk level (minimal, low, moderate, high, or extreme) and forecasts the hourly heat index throughout the entire workday, giving employers information they can use to adjust the work environment as needed to protect workers.