Crew A/C Powered Break Room Trailer Rentals in Washington

How Washington's Outdoor Heat Rule Works at 52, 80, 90 and 100 Degrees

Washington's outdoor heat exposure rule sits at WAC 296-62-095 through 296-62-09560. The permanent version employers work under today took effect on July 17, 2023, replacing a patchwork of seasonal emergency rules that had been rewritten in a hurry after the June 2021 heat dome. The rule is short, plainly written and worth reading straight through once, because most of the confusion in the field comes from people repeating a version of it they heard rather than the version that is filed.

Table 1 sets the entry point. For workers in ordinary clothing the action level is 80 degrees. For workers in nonbreathable clothes, vapor barrier clothing or PPE such as chemical resistant suits, the action level is 52 degrees. That second row is the one contractors miss. It captures refinery outage crews, abatement crews, remediation crews and anyone spending the day in rain gear, and in Western Washington it is in play for most of the year rather than a summer stretch.

The triggers are ambient air temperature. The state's compliance directive says trigger temperatures are intended to be used as ambient air temperatures, not wet bulb globe temperatures or heat indexes. That is a meaningful difference from Oregon, which runs its rule on heat index. In the dry air of the Columbia Basin the heat index often reads below the actual temperature, so Washington's threshold gets crossed earlier than a heat index threshold would on the same afternoon.

Above the action level, the rule asks for the familiar package: access to shade, the opportunity to drink at least a quart of water an hour, a written plan, annual training for employees and supervisors, and 14 days of close observation for workers who are new or returning after a week away. It also requires employers to encourage and allow a preventative cool down rest whenever a worker feels the need for one, and that rest is paid.

At 90 degrees the high heat procedures begin, and this is where the rule gets commercially interesting. WAC 296-62-09547 states that those procedures apply unless engineering or administrative controls such as air conditioning or scheduling work at cooler times of day are used to lower employee exposure below 90 degrees. The procedures include a mandatory paid cool down cadence of ten minutes every two hours at 90 degrees, escalating to fifteen minutes every hour at 100.

Run that against a real crew. A twenty person crew at 100 degrees is being paid for five hours of mandated rest across an eight hour shift. Nobody needs a vendor to tell them what that costs, and no honest vendor will promise a specific saving, because crew size, wage rates and how many days actually cross the threshold vary by site. What is worth doing is putting the rule text and your own payroll numbers side by side before the season starts.

One more line is worth knowing. Supervisor training under WAC 296-62-09560 must cover the importance of considering engineering or administrative controls such as air conditioning. The state is not neutral on this point. It writes air conditioning into the shade clause, into the high heat clause, and into the training clause, and its own compliance template names a portable air conditioned trailer as the example employers should follow.

Sources: WAC 296-62-09547, high heat procedures

Why an Unconditioned Jobsite Trailer Still Counts as Outdoors in Washington

The most common answer a Washington contractor gives when heat comes up is that they already have a trailer on site. It is a reasonable answer everywhere else. In Washington it runs into a definition most people have never read, and the definition is short enough to quote in full at a preconstruction meeting.

WAC 296-62-09520(6) defines the outdoor environment this way: work environments such as inside vehicle cabs, sheds, and tents or other structures may be considered an outdoor environment if the environmental factors affecting temperature are not managed by engineering controls. In other words, the state does not care whether a space has four walls. It cares whether anything is actively managing the temperature inside it.

The compliance directive spells out what counts. Examples of engineering controls include building insulation, fans, and air conditioning. A shed with no ventilation, a connex box baking in a laydown yard, a truck cab with the engine off, and an old jobsite office with a broken unit are all outdoors as far as the rule is concerned. A trailer with a working mini split is not.

This distinction does more than settle a definitional argument. It changes what the rest of the rule asks of you. If the space you are counting as shade is legally outdoors, it does not satisfy the shade requirement, and it does not lower employee exposure below 90 degrees for the purposes of the high heat clause. You are running the full package on paper while believing you are covered.

It also cuts the other way, which is the part worth selling internally. A conditioned space is named in the rule as an alternative to shade under WAC 296-62-09535(3), and controls that hold exposure below 90 degrees remove the mandatory cool down cadence under 296-62-09547. One decision moves you across two lines at once.

There is a practical version of this test that has nothing to do with regulations. Walk into the space at two in the afternoon in August, sit down, and time how long it takes before you want to leave. If the answer is under five minutes, your crew has already worked that out and is sitting in a truck with the engine running instead. Fuel burn, idle hours and a crew scattered across a parking area are the real costs of a break space nobody uses.

Western Washington makes this easy to underestimate, because the thermometer rarely looks alarming. Sea-Tac averages under three days a year at or above 90 degrees. But the action level for anyone in rain gear or a chemical resistant suit is 52 degrees, and a sealed unventilated box on a job site in Kent in May will sit well above the outside air by mid morning. The question the rule asks is not how hot it is outside. It is whether anything is managing the temperature in the space where your crew is supposed to recover, and a closed door with no equipment behind it manages nothing.

The state's accident prevention program addendum, the form employers actually fill in, prints the answer it expects to see. When possible, we will provide portable air conditioned trailers. When trailers are not available we will set up portable canopies with misting stations. The regulator wrote the order of preference itself, and it put the trailer first.

Sources: DOSH Directive 10.15, outdoor heat exposure

Wildfire Smoke on a Washington Job Site: What Chapter 296-820 Asks For

Heat is the first season. Smoke is the second, and in Washington it often arrives right on top of the first. State foresters reported roughly 425,000 acres burned by the end of July 2026, with ten large fires covering 200,000 acres and National Guard crews activated for ground support. Across the decade from 2015 through 2024 the state averaged about 455,000 acres a year, with a record 1,137,394 acres in 2015.

The rule that covers it is chapter 296-820 WAC, adopted permanently effective January 15, 2024 and amended in May 2025. It is worth naming the citation precisely, because several third party summaries point at the wrong chapter. Agriculture has a parallel at WAC 296-307-098 adopted on the same date.

The core obligation is at WAC 296-820-835. Where current PM2.5 reaches 35.5 micrograms per cubic meter, which corresponds to an air quality index of 101, the employer must implement effective exposure controls whenever feasible. The controls listed first are providing enclosed buildings, structures or vehicles where the air is adequately filtered, followed by portable HEPA filters in enclosed areas.

Two things about that number matter for planning. First, Washington triggers at an index of 101, fifty points below California's threshold of 151, so a smoke day that would not move the needle in Sacramento is a rule day in Wenatchee. Second, the state encourages controls even earlier, from an index of about 72, which in a bad August is most of the month east of the Cascades.

If air quality keeps climbing, respirators escalate on a ladder set out at WAC 296-820-840. Between an index of 101 and 350 the employer must provide N95s at no cost. Between 351 and 848 they must be distributed directly to each employee. Above that, a full respiratory protection program applies under chapter 296-842 WAC. Nobody wants to run a job at that level, which is exactly why enclosed space is worth having before the smoke arrives.

The sentence to build a plan around is a note in the rule itself. Exposure controls may be implemented to the extent that the work is no longer covered by the scope of this rule. An enclosed, filtered space kept closed does not simply help with a smoke day. It removes that time from the rule's scope, and WAC 296-820-805 makes the exemption for enclosed buildings kept closed explicit.

For a sense of scale, look back at September 2020. State environmental staff wrote that the majority of Washington experienced at least five consecutive days of very unhealthy or hazardous air quality, and between September 12 and 17 every air quality monitor in the state exceeded federal standards. That was the worst statewide stretch since 2000, and King County alone logged eight unhealthy or worse days that year. Planning for smoke is not planning for an unusual event any more.

There is a scheduling point buried in all of this that is easy to miss when the two rules are read separately. Heat sells from May through September and smoke lands from July through October, so the overlap in August is the month when a single enclosed, conditioned, filtered space is doing two jobs at once. Contractors who rent for the heat season and release the unit on Labor Day often end up calling back in the third week of September. If your work runs past the middle of summer, the honest planning window is May through October, not June through August.

Sources: WAC 296-820-835, wildfire smoke exposure controls

What Washington's Own Heat Illness Claims Data Says About Mild Days

Most heat safety arguments lean on extreme numbers from somewhere else. Washington does not need to borrow any, because the state's own SHARP research program published an analysis of every accepted workers compensation claim for heat related illness from 2006 through 2021. The findings are more useful than any temperature table, and they point somewhere counterintuitive.

There were 857 accepted claims across that period. Construction accounted for 216 of them, about 25 percent, the largest share of any single sector. Agriculture followed at 142 and public administration at 135. For an industry that is roughly six percent of state employment, construction carrying a quarter of the heat claims is a signal worth taking seriously.

Now the number that should change how a superintendent plans a summer. Across all sectors, 44 percent of claims happened below 89 degrees, the old trigger, and 18 percent happened below 80 degrees. In construction specifically, 16 percent of claims occurred below 80 degrees, 46 percent below 89, and 77 percent below 95. Three quarters of Washington construction heat claims happened below the temperature at which California's high heat rules even begin.

That is the honest case for a conditioned break space in a mild climate, and it does not require anyone to exaggerate. The hazard is not an exotic desert afternoon. It is an ordinary warm day worked hard, in heavy clothing, with nowhere to actually cool down and a crew that has not acclimatized because there have not been enough warm days yet this year to acclimatize on.

The extreme years still happen, and they arrive without much warning. Across Sea-Tac's full 82 year record there have been only five days at or above 100 degrees, and three of them fell inside 72 hours in late June 2021, peaking at 108. Spokane set an all time record of 109 degrees that same week in a record that starts in 1881. The SHARP data logged 34 accepted claims in the five days from June 26 to 30 alone.

The human cost of that week is documented. The state Department of Health counted 100 heat related deaths between June 26 and July 2, 2021. Heat illness emergency department visits across the federal region running Washington, Oregon, Idaho and Alaska hit roughly 69 times the 2019 baseline for June 25 through 30. The state filed its emergency heat rule on July 9, weeks later.

There is a structural reason Washington crews are exposed in a way crews in hotter states are not. As of 2023 nearly half of Puget Sound households still had no air conditioning, roughly seven times the national rate, though the share with cooling is climbing quickly. A worker who overheats during the day and then goes home to a warm house starts the next shift already behind. On site is often the only place a crew genuinely cools off.

The practical takeaway from the claims data is a planning one. If most of your heat exposure risk sits below 95 degrees, then a plan that only activates during a heat advisory is aimed at the wrong days. The days that actually generate claims in this state are the first warm stretch of the year, the shoulder weeks in June and September, and any day a crew is working hard in heavy clothing. A conditioned space that is already on site on those ordinary days is worth more than a scramble during the two weeks a year that make the news.

Sources: SHARP analysis of heat related illness claims by temperature