How to Write an OSHA Heat Illness Prevention Plan

OSHA's heat illness prevention standard is now in effect — and the first thing an inspector will ask for is your written Heat Illness Prevention Plan. Not a template you downloaded. Not a generic policy. A site-specific, documented plan that reflects the actual conditions of your worksite.

Here's exactly what that plan must contain, and how to build one that holds up.

Why the Written Plan Is Non-Negotiable

Under the federal heat standard, the written plan is the foundation of your entire heat illness program. Without it, every other effort — water stations, shade structures, toolbox talks — becomes difficult to defend in an inspection or after an incident.

The plan must be:

Written — not verbal, not informal, not "we've always done it this way"
Site-specific — reflecting the actual layout, tasks, and exposures at each location
Accessible — available to workers and their representatives on request
Updated — revised when conditions, tasks, or personnel change significantly

A single corporate template applied to every project is not a site-specific plan. OSHA inspectors know the difference.

The Six Required Elements

1. Identification of Heat Hazards

Walk every work area and identify where heat exposure is highest. This means looking at:

Tasks with high exertion — concrete work, roofing, trenching, material handling
Areas with limited airflow — enclosed structures, below-grade work, spaces between equipment
Radiant heat sources — dark roofing surfaces, metal decking, machinery exhaust
Shift timing — peak sun hours (10am–3pm) create meaningfully higher exposure than early morning or late afternoon

Use OSHA's Heat Index App to monitor daily conditions at your site and determine which trigger level applies.

Document specific tasks, locations, and the conditions that make them higher risk. This section should read like someone who actually walked the site wrote it.

2. Engineering and Administrative Controls

List the specific controls you're using, not just the categories. "Shade will be provided" is not a control. "A 10x10 pop-up canopy will be positioned within 100 feet of roofing crews during peak hours" is a control.

Engineering controls:

Air conditioning in site trailers, equipment cabs, and temporary structures
Mechanical ventilation in enclosed work areas
Reflective or insulated surfaces to reduce radiant heat
Cooling stations with misting fans

Administrative controls:

Scheduling high-exertion tasks before 10am or after 3pm
Job rotation to limit individual exposure time on high-heat tasks
Buddy system or direct supervisor monitoring during High Heat Trigger conditions
Mandatory rest ratios matched to heat index and exertion level

3. Water and Rest Procedures

The standard requires cool drinking water (no warmer than 77 degrees F) at no cost to workers, with enough volume for each worker to drink at least 1 quart per hour during high heat conditions.

Your plan must document:

Where water stations are located relative to each work area
How often water is restocked and by whom
The rest break schedule at the Initial Heat Trigger (80 degrees F) and High Heat Trigger (90 degrees F)
Who is responsible for monitoring compliance

One cooler at the job trailer for 20 workers does not meet the standard. Workers who have to walk more than a short distance to access water simply won't do it when they're busy. Plan accordingly.

4. Acclimatization Protocol

This is the section most plans get wrong — or skip entirely. Acclimatization is the process of gradually exposing workers to heat so their bodies adapt. It is not optional, and failing to implement it is how healthy workers end up in the hospital.

Under the standard (see OSHA's acclimatization guidance):

Day 1: No more than 20% of normal workload duration in heat
Days 2-14: Workload increases incrementally until full capacity is reached

This applies to:

New hires starting their first days on an outdoor site
Workers returning after 14 or more consecutive days away from heat exposure
Workers moving from an indoor or low-heat assignment to an outdoor or high-heat task

Your plan must describe how acclimatization is tracked, who is responsible for monitoring new and returning workers, and how production schedules are adjusted to accommodate it. Build it into your onboarding process. A new subcontractor crew cannot go to full production in 100-degree heat on day one.

5. Emergency Response Procedures

Heat stroke is a medical emergency. Core body temperature above 104 degrees F, combined with neurological symptoms — confusion, slurred speech, loss of consciousness, stopped sweating — requires immediate action.

Your emergency response section must include:

Who calls 911 — designate a specific role, not "someone"
How to direct EMS to the exact work location — on a large site, "construction site on Main Street" is not enough. Know your cross streets, gate numbers, and which part of the site the crew is on
First aid while waiting — move the worker to a cool location, apply ice packs to neck, armpits, and groin, use a cooling fan if available, monitor breathing
Who has first aid and CPR certification — document names and current certification dates
Hospital location — know the nearest emergency room before you need it

Test this plan. Walk a new supervisor through it. Ask them where they'd direct EMS to find the north side crew. If they don't know immediately, you have a gap.

6. Heat Safety Coordinator Designation

The standard requires a designated Heat Safety Coordinator on each site. This person can be a foreman, superintendent, or other qualified individual — they do not need to be a dedicated safety hire. But they must be trained, and their responsibilities must be documented.

Daily coordinator responsibilities:

Monitoring the heat index before work begins and at regular intervals throughout the day
Enforcing water availability and rest break schedules
Observing new and acclimatizing workers closely during their first two weeks
Recognizing heat illness symptoms and initiating emergency response
Logging daily conditions, any heat-related complaints, and corrective actions taken

Document the coordinator's name, their training, and the date of designation. Update it when personnel change.

Common Mistakes That Get Contractors Cited

Using a template as-is. A downloaded heat illness prevention plan with your company logo on it is still a template. Inspectors are familiar with the common ones. Site-specific details are not optional.

No acclimatization records. You cannot prove your acclimatization protocol was followed if you have no documentation. Track new and returning workers for their first two weeks in heat.

Water that isn't actually accessible. Citing "water provided" in your plan while the actual cooler is empty, warm, or located far from where workers are performing high-exertion tasks is a citation waiting to happen.

A coordinator who doesn't know they're the coordinator. Designating someone on paper without training them or telling them is not compliance. Review OSHA's enforcement priorities to understand how heat citations are classified.

Not updating the plan. If your site layout changes, new high-heat tasks are added, or your coordinator changes, the plan must be updated. A plan written in April that doesn't reflect June conditions is a gap.

Building the Plan

The best heat illness prevention plans are written by someone who has walked the site — who knows where the shade is, where the hottest tasks happen, how long it actually takes to get from the work area to the water station, and where EMS would need to go in an emergency.

Greenberg Safety develops site-specific Heat Illness Prevention Plans that meet the 2026 OSHA standard — including written plan drafting, coordinator training, documentation systems, and pre-season site audits for Texas contractors and teams nationwide.

Schedule a consultation or call (512) 585-7070 to get your plan in place before summer inspection activity picks up.

OSHA resources: Heat Illness Prevention · Heat Index App · Acclimatization Guidance · Heat Standards · OSHA Penalties