Heat Risk Assessment Checklist for Employers

What a heat risk assessment actually is

A heat risk assessment is a written review that answers four questions for your specific workplace: Where are employees exposed to heat? Who is most at risk? What controls are in place? What happens if something goes wrong? It is not a generic checklist you download and file — it is a short, site-specific document that names real tasks, real people, and real numbers.

Good assessments are short enough to actually be used. A one- to three-page document that a supervisor can reference during a hot afternoon is far more valuable than a 40-page binder that lives in a back office.

When to perform one — and how often to update it

Complete the first assessment before the first hot stretch of the year, not during it. Review it at least annually, and re-open it any time the work, the workforce, or the site changes meaningfully: a new shift pattern, a new line of business, a renovation that changes ventilation, a heat-related incident or near-miss, or a sudden heatwave that exposes a gap.

Indoor vs outdoor workplaces

Outdoor work draws the most attention, but indoor heat is consistently the most underestimated risk. Warehouses, commercial kitchens, laundries, manufacturing floors, and delivery vans routinely exceed the heat-index thresholds OSHA uses for outdoor work — often without any of the obvious cues (sun, sweat, visible exertion) that prompt action outdoors.

Identifying heat hazards by task and location

Walk the site with a supervisor and list every task where employees are exposed to heat for more than 15 minutes in any hour. For each task, capture the location, typical duration, physical exertion level, PPE worn, and the heat-index range you've observed. This list — not a generic risk score — is what the rest of the assessment hangs on.

High-risk employees

Heat doesn't affect everyone equally. The assessment should identify, without singling people out unfairly, which roles or situations carry elevated risk: new hires in their first two weeks, employees returning from time off, anyone over 65, pregnant employees, employees with known cardiovascular conditions, anyone on medications that affect hydration or heat tolerance, and employees wearing heavy PPE.

The practical output is a stronger acclimatization protocol and a clear expectation that supervisors check in more often with anyone in those situations during high-heat days.

Work schedules and rest breaks

Document the rest-break schedule you actually follow at each heat-index trigger — not the one you intend to follow. At the high-heat trigger (around 90°F heat index), a paid 15-minute rest break every 2 hours is the practical floor. Build the schedule into the shift, not into individual discretion: 'take a break if you need one' is not a defensible policy.

Where possible, shift physically demanding work earlier in the day, rotate employees through cooler tasks, and avoid scheduling new hires onto the hottest crews during their acclimatization period.

Hydration planning

Cool drinking water — not just any water — should be within easy reach of every work area. Plan for at least one quart per employee per hour during heat exposure, and assign someone to check and refill stations during the shift. Sports drinks or electrolyte options are appropriate when work is sustained and sweat losses are heavy, but they don't replace water.

Emergency response planning

Every assessment needs a one-page emergency response procedure posted where staff actually work. It should distinguish heat exhaustion from heat stroke in plain language, state when to call 911 (any altered mental status, any loss of consciousness, any seizure), and name the on-shift manager responsible. Cooling supplies — ice, cold water, towels, a shaded or air-conditioned space — should be identified and accessible, not theoretical.

Training employees and supervisors

Training is what turns the assessment from a document into a behavior. At minimum, every employee should be trained on the symptoms of heat illness, the buddy system, the rest-break schedule, where water and cooling are located, and the emergency procedure. Supervisors need the same plus the authority — explicitly — to call breaks and stop work when conditions warrant.

Keep records: date, topics covered, attendees, and the language training was delivered in. If it isn't documented, OSHA treats it as if it didn't happen.

Documentation for compliance

The assessment, the written heat plan, daily heat-index logs, training records, and any incident or near-miss reports together form the documentation an inspector will ask for. Keep them in one place — physical or digital — that a supervisor can produce in minutes, not days. State programs (California, Washington, Oregon, Colorado, Minnesota, Nevada, Maryland and others) may require additional documentation; plan to the stricter rule where multiple apply.

For a deeper walkthrough of what OSHA is moving toward federally, see our companion guide, OSHA Heat Rule Explained.

Reviewing and updating the assessment

Set a calendar reminder for an annual review in early spring, before the first hot stretch. Re-open the assessment immediately after any heat-related incident or near-miss, any significant change to staffing or operations, and any time a heatwave exposes a gap the current plan didn't anticipate. A living document is worth far more than a perfect one filed away.