If your crew is working attics, rooftops, or unshaded commercial units this summer, you're operating in what OSHA classifies as extreme heat environments. Attic temperatures routinely exceed 130°F by noon in Southern markets, and even moderate 85°F outdoor temps create heat index readings over 100°F when you factor in humidity and radiant load from equipment. OSHA doesn't have a specific heat standard yet, but they're using the General Duty Clause to cite contractors — and inspections are up 40% year-over-year in construction trades.

The core requirement is a written heat illness prevention program. That means documented acclimatization schedules for new hires and returning workers (OSHA wants 20% workload on day one, building to 100% by day four), mandatory water access at every jobsite (one quart per employee per hour), and scheduled rest breaks in shaded or air-conditioned areas. If you're running a two-man install crew in July and you don't have a cooler, shade structure, and a break protocol, you're exposed.

Acclimatization is where most contractors fail audits. Your best installer coming back from a week vacation isn't acclimated anymore — physiologically, he's starting over. OSHA wants supervisors trained to recognize heat illness symptoms: confusion, lack of sweating, nausea, elevated heart rate. If a tech says he's dizzy and you send him back up the ladder, that's a willful violation, and fines jump to six figures.

Here's what to do this week: Download OSHA's Heat Illness Prevention campaign materials (free at osha.gov), print the acclimatization table, and laminate it for every truck. Stock each van with a 5-gallon water cooler, electrolyte packets, and a thermometer so your lead tech can log heat index readings. Add a line item to your safety meetings: 'Who's new or returning from time off?' Those employees get modified schedules. Train every crew lead on the difference between heat exhaustion (cool, clammy skin) and heat stroke (hot, dry skin, altered mental status) — heat stroke is a call-911 event, and minutes matter.

Expect OSHA to finalize a federal heat standard by 2026. California, Washington, and Oregon already have enforceable rules with specific temperature triggers and mandatory cool-down periods. If you operate in multiple states, you need to know which jurisdiction's rules apply on every job.