Heat Stress Awareness: What Road, Utility and Construction Crews Need to Know

A paving crew working beside live traffic has a different heat problem than a utility crew restoring service after a storm. An aircraft marshaller standing on the hot tarmac has a different heat exposure than a maintenance technician working inside a hangar.

That’s why heat stress awareness can’t stop at “drink water and watch for symptoms.” For road, utility and construction crews, heat stress awareness needs to become part of a practical heat illness prevention plan that supervisors can apply to each shift. Supervisors need to look at the weather, the work, the crew and the gear before heat illness shows up in the middle of the shift.

Key Takeaways

• Heat stress planning should happen before the work starts, not after a worker reports symptoms.
• OSHA does not have a final federal heat standard yet, but heat remains an active OSHA rulemaking and enforcement priority.
• New, returning and reassigned workers need extra attention during hot weather.
• Water, rest and shade only work when crews can actually access them during the shift.
• A heat stress mitigation plan should account for the day’s workload, crew readiness, recovery options and required clothing or PPE.

What Does Heat Stress Awareness Mean for Outdoor Crews?

For outdoor crews, heat stress awareness means knowing how heat exposure will affect today’s work, not just knowing the signs of heat exhaustion.

NIOSH defines occupational heat stress as the combination of metabolic heat, environmental heat and clothing or PPE that increases heat stored in the body. That definition fits road, utility and construction work well because the heat load rarely comes from one source.

Clothing is part of that heat load from the moment the shift starts. NIOSH recommends breathable, light-colored and loose-fitting clothing where the work allows it. Breathable fabrics help sweat evaporate, lighter colors absorb less radiant heat from the sun, and a looser fit allows more air to move between the clothing and skin. Protective clothing and PPE can add to heat stress, so apparel selection should be part of the heat illness prevention plan, not an afterthought.

A road crew may be working in direct sun on pavement, beside idling vehicles or equipment, under a hard hat and in high-visibility clothing. Transportation work could involve directing aircraft on a ramp, handling cargo at a port or responding to a roadside breakdown. Utility and construction crews may be hand digging, running a saw or pulling cable. In each case, the combination of conditions, workload and required gear can raise the heat load quickly.

The question for the supervisor is simple: What makes this shift hot, and what are we changing because of it?

That question should lead to specific field decisions, such as:

• Moving heavier work to earlier in the day
• Rotating workers through high-exertion tasks
• Staging water closer to the active work area
• Planning recovery breaks before workers show symptoms
• Watching new or returning workers who may try to keep up too soon

These decisions turn a written heat illness prevention plan into something crews can use in the field. The goal is to adjust the shift before heat starts making decisions for the crew.

Why Are Road, Utility and Construction Crews at Higher Risk?

These crews often work where heat controls are harder to manage. The work moves. Shade may be limited. Traffic control has to stay covered. Utility outages create urgency. Construction schedules do not pause just because the heat index climbs.

The exposure is also routine. The Bureau of Labor Statistics reported that 33% of workers were exposed to the outdoors as a regular part of their job in 2023, and construction laborers were among the occupations with at least 99.5% outdoor exposure.

Construction also carries a heavy share of heat-related fatalities. CPWR reported that construction accounted for 34% of fatal heat-related injuries in the U.S. in 2023.

Those numbers shouldn’t just raise concern. They should push teams to plan for the heat exposure crews face during real work. A crew paving blacktop, setting up a lane closure or pulling storm restoration work needs controls that match the conditions in front of them.

Heat also creates secondary safety problems. NIOSH notes that heat can contribute to sweaty hands, slipping, fogged safety glasses, dizziness, fatigue and PPE being loosened or removed. On a road, utility or construction crew, those problems can affect equipment work, hand safety, traffic exposure and decision-making.

What Does OSHA Expect Employers to Know About Heat Exposure?

Employers should treat heat as an active safety and compliance issue, even though federal OSHA’s heat rule is not final.

Here’s what safety and operations leaders should know:

• Federal OSHA has proposed a heat rule: OSHA published its Heat Injury and Illness Prevention proposed rule in August 2024. OSHA’s rulemaking page states that the proposed standard would apply to outdoor and indoor work in general industry, construction, maritime and agriculture where OSHA has jurisdiction.
• Heat remains an OSHA enforcement priority: OSHA updated its National Emphasis Program for heat hazards in April 2026. The update focuses inspection and outreach efforts on high-risk industries and notes that compliance officers may conduct random heat-focused inspections in high-risk industries when the National Weather Service issues a heat advisory or warning.
• Some states already have heat exposure standards: OSHA’s heat standards page lists several states with heat exposure standards, including California, Colorado, Minnesota, Oregon and Washington.
• Heat exposure involves more than the forecast: The OSHA-NIOSH Heat Safety Tool can help supervisors check the local heat index and review recommended precautions. Employers still need to consider the work being performed, direct sun, airflow, acclimatization and clothing or PPE when evaluating the crew’s actual exposure.

For a safety manager, the takeaway is simple: don’t wait for the federal rule to become final before reviewing the company’s heat illness prevention plan. Check federal OSHA guidance, state-plan requirements, customer rules and the actual work conditions crews face.

What Should Supervisors Check Before and During the Shift?

A written heat stress mitigation plan provides the framework, but supervisors still have to apply it before and during the shift. 

They don’t need a complicated system, but they do need a routine that looks beyond the forecast. Tools like the OSHA-NIOSH Heat Safety Tool can help with the initial heat check, but supervisors still need to account for workload, direct sun, hot surfaces, airflow, clothing and PPE.

Use a short pre-shift check like this:

Field Check	What to Ask Before Works Starts
Weather and work area	Will crews work in direct sun, on pavement, around equipment or in areas with limited airflow?
Task intensity	Who is doing the highest-exertion work, such as shoveling asphalt, hand digging, lifting materials or setting traffic control?
Crew readiness	Who is new, returning from time away or reassigned to hotter work than usual?
Water access	Is cool water close enough that workers will actually drink it during the shift?
Rest and shade	Where will workers recover, and will breaks increase as heat stress rises?
Emergency response	Who calls EMS, who gives directions and what symptoms trigger immediate action? Are workers trained to recognize heat stress in their work partners?
Clothing and PPE	Does required gear add heat burden or make workers likely to loosen or remove it?

OSHA says employers should provide cool water near the work, encourage workers to drink frequently and provide electrolyte-containing fluids for work lasting more than two hours. OSHA also says rest break length and frequency should increase as heat stress rises, and workers should have a cool place to recover.

New and returning workers need a separate look. OSHA and NIOSH recommend the Rule of 20 Percent, where new workers start with 20% of the normal work duration in heat on day one and increase by 20% each additional day. OSHA notes that some workers may need up to 14 days to adapt.

A new laborer may want to prove they can keep pace with the experienced crew, especially during hand digging or material handling. The supervisor has to manage that exposure instead of waiting for the worker to ask for help.

How Should Safety Teams Think About High-Visibility Apparel in Hot Weather?

High-visibility apparel is one equipment decision inside the larger heat stress mitigation plan. Road, utility and construction crews still need to be seen around traffic and equipment, even when hot conditions make required clothing harder to wear.

The MUTCD Part 6 requires workers within the right-of-way and temporary traffic control zones to wear high-visibility safety apparel meeting ANSI/ISEA 107 Performance Class 2 or 3 requirements, depending on the work and exposure.

But the issue is how that apparel behaves in hot conditions. If workers have to layer a vest over a heavy shirt, they may unzip it, take it off during “quick” tasks or avoid wearing it correctly. That creates a different problem around high traffic zones, mobile equipment and low-light work.

When safety and procurement teams evaluate hot-weather high-vis apparel, they should look beyond class and price. Ask:

• Does the garment match the required visibility class for the work?
• Does it reduce unnecessary layering where appropriate?
• Does it offer breathable construction for hot-weather use?
• Does it offer built-in sun protection?
• Does it fit the task, such as flagging, utility work, construction labor or supervisory work?
• Will workers keep it on and wear it correctly through the shift?

Once the core controls are in place, clothing decisions can support the heat illness prevention plan instead of working against it.

Where Kishigo Cool Touch Fits Into Hot-Weather High-Vis Planning

For crews working in hot conditions, the line offers several practical options:

On hot days, crews still need high-visibility apparel that performs around vehicles, equipment and low-light conditions. But heavy fabrics and extra layers can make that gear harder to wear correctly through a full shift.

Kishigo's Cool Touch line was developed with that problem in mind. It gives safety and procurement teams a way to consider comfort and wearability alongside visibility class and price.

The fabric also has comparative testing behind it. Cool Touch delivered nearly 7% higher total heat loss and a 43% greater initial cooling sensation in Q-Max testing. Put simply, it transfers heat more effectively and feels cooler when it first touches the skin.

For crews working through hot shifts, Cool Touch gives teams several ways to match the garment to the work:

• Reduce extra layers: Where the selected style meets the visibility requirements of the job, Cool Touch hi-vis shirts can eliminate the need to wear a separate shirt and vest.
• Manage heat and moisture: Moisture-wicking fabric, micro mesh in high-heat areas and breathable reflective material help move moisture and heat through the garment.
• Choose the right coverage: The line includes short sleeve and long sleeve T-shirts, a long sleeve hoodie T-shirt and a short sleeve polo.
• Match the visibility requirement: We offer ANSI/ISEA 107-2020 Type R Class 2 and Class 3 options, depending on the style.

Water, rest, shade, acclimatization and supervision still form the foundation of a heat illness prevention plan. But when crews need to wear hi-vis apparel all day, choosing a garment designed for hot conditions can remove one barrier to wearing it correctly through the full shift.

Explore Kishigo Cool Touch to find tested, breathable high-visibility apparel for transportation, utility and construction crews working in hot conditions.

FAQ

Does OSHA have a federal heat stress standard?

Federal OSHA has not finalized a heat stress standard as of the current OSHA heat rulemaking status page. OSHA published a proposed rule in August 2024 and completed the public hearing process in 2025. Employers should still follow OSHA guidance and check state-plan requirements.

What is the OSHA/NIOSH Rule of 20 Percent?

The Rule of 20 Percent is an acclimatization approach for new workers. OSHA and NIOSH recommend that new workers start with 20% of the normal work duration in heat on day one, then increase by 20% each additional day.

How often should outdoor crews take breaks in hot weather?

There is no single break schedule that fits every job. OSHA says rest break length and frequency should increase as heat stress rises. Workload, humidity, sun exposure, PPE, worker condition and recovery location all affect break needs.

What are warning signs of heat exhaustion and heat stroke?

Warning signs can include heavy sweating, weakness, dizziness, headache, nausea, confusion, fainting or loss of coordination. Heat stroke is a medical emergency. OSHA’s heat illness and first aid guidance should guide training and response planning.

Can high-vis cooling apparel prevent heat illness?

No. Breathable or moisture-wicking high-vis apparel may support comfort and correct wear, but it does not replace water, rest, shade, acclimatization, supervision or emergency response. NIOSH includes clothing and PPE as part of occupational heat stress, so apparel belongs in the planning conversation.