After an analysis of 25 OSHA-documented heat-related illnesses — 14 fatal and 11 nonfatal — the Centers for Disease Control suggested that employers start screening their workers for heat stress when the heat index reaches 85 degrees Fahrenheit rather than the 91 F OSHA currently recommends. Heat stress covers a wide variety of potential illnesses, including life-threatening heat stroke.

The CDC's review was intended to test its own NIOSH recommended occupational exposure limits, which take factors like levels of heat acclimation, the type of work clothing and worker predisposition to heat illness into consideration in a real-world setting. Of the 25 cases being analyzed, six fatalities occurred when the heat index was less than 91 F, and four fatalities occurred when the heat index was between 85 F and 90 F. Heat index screening should be used when the wet bulb globe temperature method is unavailable. The wet bulb globe temperature method measures the heat stress in direct sunlight via temperature, wind speed, humidity, sun and cloud cover.

So that workers don't succumb to a heat-related illness, OSHA recommends that employers implement an acclimatization program that gets workers used to being in the heat little by little, provide first aid training, make sure workers drink plenty of fluids and give employees rest breaks in a shaded area. 

OSHA recommends that workers and onsite supervisors be trained to recognize the signs of heat stroke (body temperature rises to 104 F, confusion, loss of consciousness, seizures, no sweat) and heat exhaustion (body temperature of greater than 100.4 F, headache, nausea, dizziness, weakness, irritability, confusion, thirst, heavy sweating). Workers experiencing these symptoms should be taken to a shady area and treated with cold compresses — and in the case of heat exhaustion, be given something to drink — and then taken to an emergency room.

Other less serious heat-related illnesses are heat cramps and heat rash. Heat cramps can be treated with frequent fluid intake — water and/or carbohydrate-electrolyte drinks like Gatorade. The best remedy for heat rash is to keep affected areas dry and as cool as possible. Workers can apply powder but no creams or lotions.

Even without a specific heat illness prevention regulation, OSHA cited Middleburg, Florida-based Southeastern Subcontractors with a serious violation after one of its workers died from heat stroke, also called hyperthermia. OSHA said the company failed to protect its workers from the heat. The agency also cited Southeastern for failing to report a workplace death to OSHA within 8 hours after the accident and fined the company a total of $22,173. The agency uses its General Duty to protect workers clause in such cases.