Outdoor workers are at risk for heat exposure illness if they spend a significant part of their shift
outdoors. If workers have significant time in the direct sunlight executing strenuous tasks for long
periods of time or if the tasks at hand require heavy clothing (personal protective equipment) they are at even greater risk.
Workers working outside should follow a work/rest schedule. If the rest period can’t be in air
conditioning it should be in full or complete shade or an area providing a cooling breeze and should have
access to an ample supply of cool drinking water. Following the work/rest schedule includes
distributing the workload evenly over the course of the day to incorporate the work/rest cycle. Rest
periods aren’t a work stoppage these times of “rest” can include taking time out of direct heat to do
paperwork, training or meetings. Work/Rest periods are based on: if the temperature rises, humidity
increases, the sun gets stronger, there is no air movement, workers are wearing heavy ppe gear work for
Planning for a high heat index (calculated based on temperature & humidity) should include Hot
weather supplies such as water and area for shade, an EAP (emergency evacuation plan) for heat-
related illness, Schedule to acclimate workers to the heat. Determine in advance hot weather will
modify workflow and schedules, Provide training on identifying heat-related illnesses, Arrange for an
enforcer on site to follow the work/rest plan.
How do you recognize heat-related illness? If someone has Heat (stress) Exhaustion he or she may
experience: a headache, fainting, dizziness, wet skin, weakness, confusion or irritability, vomiting,
nausea or extreme thirst and excessive sweating. More dangerous than Heat Stress is Heat Stroke
these symptoms include: unable to think clearly, passing out, collapsing or having a seizure. The body
may be going into shock, the person may stop sweating. If you or someone you work with has
symptoms of heat-related illness: Find someone on site who is trained in First/Aid or if no one is
available to call 911, move the worker to a cooler area, apply wet towels or fan the worker, provide cool
drinking water or an electrolyte drink if the worker is able. Heat stroke is extremely dangerous and
requires immediate medical attention.
OSHA has a great tool for measuring the heat index. It’s a free heat index App. It will provide the current heat index and will provide some of the tips I’ve outlined above.