Heat Stress During a Roof Replacement
A crew of five is replacing a flat roof in July. Forecast high is 36 C with 55% relative humidity; the roof surface is measured at 58 C at midday. Work is paid by the square, so the crew skips breaks to finish. Water is available in a cooler at the ground-level truck, a 5-minute walk and two ladder climbs away. Two workers are new to the crew this week. By early afternoon one worker is confused, has stopped sweating, and has hot, dry skin; a second is cramping and nauseated. The supervisor radios for a nurse and tells everyone to 'drink more water.'
1. Differentiate the two workers' conditions and state the immediate actions for each. What is the supervisor's error?
Read the worked answer
The two presentations are not the same severity. The confused worker with hot, dry skin and no sweating shows signs consistent with heat stroke, a medical emergency: altered mental status plus elevated core temperature. Immediate actions are to call emergency medical services, begin active cooling without delay (cold water immersion if available, otherwise ice packs to neck, armpits, and groin, fanning, and wetting), and continue cooling during transport. Do not give fluids to a confused worker; do not leave them alone.
The second worker has cramping and nausea, consistent with heat exhaustion and heat cramps. Move to shade, loosen clothing, cool actively, and give fluids if fully alert. Monitor for deterioration; if confusion or loss of sweating develops, escalate to heat stroke response.
The supervisor's error is treating this as a hydration problem. Water is not the primary failure here: it was 5 minutes and two ladders away, so access was effectively blocked. 'Drink more water' does nothing for a worker who is already confused and cannot safely drink, and it ignores the need for cooling, work-rest cycles, acclimatization, and shade.
2. Design the preventive controls for this job. Address workload, acclimatization, and the piece-rate incentive.
Read the worked answer
Prevention must address the conditions that produced the event, not just the individuals.
Work-rest and scheduling: shift heavy work to early morning and evening; schedule mandatory rest in shaded or cooled areas with duration based on heat index and workload; provide shade on the roof, not at the truck. Water and electrolyte fluids should be within arm's reach at the work location, not two ladders away.
Acclimatization: the two new workers are at elevated risk. Implement a graduated ramp-up over 1-2 weeks, with closer supervision and reduced load in the first days, and pair them with experienced workers.
Piece-rate incentive: paying by the square rewards skipping breaks and is a direct cause of the behavior. Remove or restructure the incentive so rest is not penalized, and make clear that stopping for rest is expected, not tolerated.
Monitoring and response: use a buddy system, symptom checks, a written heat plan with trigger thresholds, trained supervisors empowered to stop work, and a posted emergency response with cooling supplies on the roof. Document the plan and review it after each heat event.