Is Heat Illness OSHA Recordable? How to Log Heat Cases Under the 2026 Heat NEP

A worker on your crew gets dizzy and nauseous on a 95-degree afternoon. Your supervisor moves them into the air conditioning, has them drink water, and they recover within the hour. Recordable?

Now change one detail. The same worker is taken to urgent care, where a physician administers intravenous fluids. Same heat, same symptoms, same recovery. This second case is recordable, and the first one is not.

The line between those two outcomes is the entire subject of this post — and it matters more this summer than it has in years. On April 10, 2026, OSHA signed an updated Heat National Emphasis Program, and the directive contains an instruction that should get every small employer's attention: when an inspector arrives for a heat-related inspection, the first thing they do is pull your OSHA 300 Log.

The Two Questions That Decide Every Heat Case

Heat illness recordability comes down to the same two-part test that governs every entry on your 300 Log.

First, is the case work-related? Under 29 CFR 1904.5, an injury or illness is presumed work-related if an event or exposure in the work environment either caused or contributed to it. If the heat exposure happened on the job — outdoors in the sun, in an un-air-conditioned warehouse, in a commercial kitchen — work-relatedness is presumed. There is no separate "heat" exception in the rule.

Second, does the case meet one of the general recording criteria in 29 CFR 1904.7? A case is recordable if it results in death, days away from work, restricted work or job transfer, medical treatment beyond first aid, loss of consciousness, or a significant injury or illness diagnosed by a physician or other licensed health care professional.

For most heat cases, both questions hinge on a single line in the regulation that draws the boundary between first aid and medical treatment.

What Counts as a Heat Illness for Recordkeeping

Not every complaint about the heat is a recordable illness, but the range of conditions that can qualify is broader than many employers assume. OSHA has long treated the recognized clinical heat conditions — heat rash, heat cramps, heat exhaustion, and heat stroke — as occupational illnesses when they are work-related and meet a recording criterion.

The severity ladder runs from mild to life-threatening. Heat rash and heat cramps sit at the lower end and frequently resolve with first aid alone. Heat exhaustion is more serious and often involves medical treatment. Heat stroke is a medical emergency, almost always recordable, and can be fatal.

A purely subjective complaint with no diagnosed condition and no treatment beyond rest and fluids generally does not become a recordable case. The recordability turns on what happened next — the treatment, the work impact, or a clinical diagnosis — not on the fact that the employee felt unwell in the heat.

The First-Aid Line That Decides Most Heat Cases

Here is the rule that resolves the majority of heat cases. Under 29 CFR 1904.7(b)(5)(ii), OSHA maintains a finite, exhaustive list of treatments that count as first aid. One item on that list is specific to heat:

Drinking fluids for relief of heat stress.

If the only treatment a worker receives is being moved to a cooler area, allowed to rest, and given fluids to drink, the case is first aid — and not recordable, provided it does not also involve days away, restricted duty, or loss of consciousness.

The moment treatment goes beyond that list, the case becomes recordable. OSHA's own heat guidance is explicit on the most common escalation: if a worker requires intravenous fluids to treat a heat-related illness, the case meets the general recording criteria. Supplemental oxygen, prescription medication, and any treatment not on the first-aid list all cross the same line.

This is also why the professional who provides the treatment does not change the answer. OSHA has stated that the treatments on the first-aid list remain first aid even when a physician administers them — and treatment beyond that list is medical treatment even when a non-professional provides it. A paramedic handing a worker a bottle of electrolyte solution is first aid. A first-aid-trained supervisor starting an IV line — were that to happen — would not be.

For a fuller treatment of where this line falls across all injury types, see our guide on first aid vs. medical treatment.

Which Column Does Heat Illness Go In?

This trips up employers who are used to logging cuts, sprains, and fractures as injuries. Heat illness is an illness, not an injury, for recordkeeping purposes — because it results from non-instantaneous exposure to the heat environment rather than a single instantaneous event.

On the OSHA 300 Log, that means a recordable heat case is classified in the illness column for "all other illnesses," not in the injury column. You then complete the severity classification based on the outcome: death, days away from work, restricted work or transfer, or other recordable case. Getting the injury-versus-illness classification right matters because it carries through to your 300A annual summary totals.

If you are working through the mechanics of the log itself, our step-by-step OSHA 300 Log guide walks through each column.

The Reporting Clock Is Separate — and Shorter

Recording a case on your 300 Log is a different obligation from reporting a severe incident to OSHA, and the reporting clock is much shorter.

Under 29 CFR 1904.39, any work-related fatality must be reported to OSHA within 8 hours, and any work-related in-patient hospitalization, amputation, or loss of an eye must be reported within 24 hours. A heat stroke that puts a worker in the hospital triggers the 24-hour reporting requirement regardless of how it is eventually classified on the log. A heat-related death triggers the 8-hour requirement. Reports can be made by phone at 1-800-321-OSHA or through OSHA's online reporting portal.

This obligation applies even to employers who are otherwise partially exempt from routine recordkeeping. Reporting and recording are two separate duties.

What the 2026 Heat NEP Changes About Your Log

OSHA's updated Heat National Emphasis Program, signed April 10, 2026, runs for five years and directs inspection resources to 55 high-risk industries in both indoor and outdoor settings, using OSHA and Bureau of Labor Statistics data from 2022 through 2025.

The part that matters for recordkeeping is how the program uses your 300 Log. The directive instructs compliance officers conducting a heat-related inspection to review the OSHA 300 Logs and 301 Incident Reports for any entries indicating heat-related illnesses. At the opening conference, that review covers the three calendar years before the inspection plus the current year to date. Your log is no longer a back-office document — it is the first exhibit in a heat inspection.

The program also defines a "heat priority day" as a day when the heat index is expected to reach 80 degrees Fahrenheit or higher. On those days, OSHA may expand an inspection that started for an unrelated reason into a heat inspection where there is evidence of a problem — and entries on your 300 and 301 forms are explicitly named as the kind of evidence that can trigger that expansion.

There is a practical tension here worth naming. An accurate log that shows recorded heat cases is not an admission of wrongdoing — it is evidence you are tracking and managing the hazard. An empty log at an employer whose workers clearly face heat exposure invites a harder look, not an easier one. The goal is accurate recording, not a clean-looking log.

This is the same data ecosystem behind OSHA's broader targeting efforts. The injury and illness data you submit annually also feeds the Site-Specific Targeting program — we cover how that works in how OSHA picks who to inspect.

Edge Cases Small Employers Actually Hit

A few situations come up often enough to address directly.

A worker with a pre-existing condition. If work-related heat exposure significantly aggravates a pre-existing condition, the case is recordable under the significant-aggravation rule in 1904.5(b)(4). The pre-existing condition does not break the chain of work-relatedness.

A brand-new employee who has not acclimatized. Acclimatization status does not change the recordability analysis. A worker who collapses from heat on their second day is just as much a work-related case as a ten-year veteran. New and returning workers are at elevated risk precisely because they have not adapted — but that is a prevention concern, not a recordkeeping exception.

Indoor heat. Heat illness in a warehouse, foundry, laundry, or commercial kitchen is recordable on the same terms as outdoor heat. Employers sometimes miss indoor cases because they associate heat illness with the sun. The rule does not.

The worker sent home for the day. If a worker is simply sent home to rest and recover with no medical treatment beyond first aid, that alone usually does not make the case recordable. But if the recovery extends into a scheduled workday they would otherwise have worked, you may be looking at a day away from work — which is a recording criterion on its own. Track the calendar, not just the treatment.

The Bottom Line

When a heat case lands on your desk this summer, work through three questions in order. Was it work-related? For on-the-job heat exposure, presume yes. Did treatment go beyond drinking fluids and resting in a cool place — IV fluids, oxygen, prescription medication, loss of consciousness, days away, or restricted duty? If yes, it is recordable. And if it is recordable, log it as an illness in the "all other illnesses" column, not as an injury.

Keep the log current as cases happen rather than reconstructing it at year-end. Under the 2026 Heat NEP, if an inspector arrives on a hot day, your 300 Log is the first thing they will ask to see — and an accurate, well-maintained log is the easiest part of that conversation to get right.

This post covers recording heat cases after they happen. For building a heat prevention program before one occurs, see our companion guide on OSHA's Heat Illness Prevention Standard.