Heat at work: what NR-9 requires as heat waves are forecast in Brazil

The 2026 summer is expected to be hotter than normal in most of Brazil. The climate bulletin released by the federal government on October 29, 2026, prepared by CPTEC/Inpe (the weather and climate center of Brazil's National Institute for Space Research), Inmet (the National Institute of Meteorology) and Funceme (the Ceará state meteorology foundation), forecasts temperatures 1°C to 2°C above average in practically the whole country for November, December and January, with an anomaly of 2°C to 3°C in part of Pará state. The bulletin also warns of atmospheric blocking that may favor heat waves, especially in the central part of the country.

For companies with teams at client sites, the warning has a direct effect. Security guards in guardhouses, doormen, outdoor cleaning crews, gardeners, building maintenance staff and parking lot access controllers spend much of their shift in the sun. The Normas Regulamentadoras (NRs), Brazil's occupational safety and health standards issued by the Ministry of Labor and Employment (MTE), already say what the company must do in these cases. And a change to NR-24, on the water provided to workers, takes effect on January 12, 2027, in the middle of the season.

What NR-9 says about heat

Annex III of NR-9 covers occupational exposure to heat. In the text's own words, it applies "wherever there is occupational exposure to the physical agent heat", with no distinction between indoor and open-air settings. Heat is part of the Risk Management Program (PGR, Programa de Gerenciamento de Riscos) required by NR-01, and the core rule is simple: the company must adopt prevention measures so that exposure does not cause adverse health effects for the worker (item 3.1).

The annex calls for four lines of work:

• Worker guidance (item 3.1.1): what increases the risk, the signs and symptoms of heat-related disorders, the need to tell a supervisor or physician when they appear, the prevention measures and what to do in an emergency. When the prevention measures call for it, specific training must be annual (item 3.1.2).
• Exposure assessment (items 3.2 and 3.3): it starts with a preliminary assessment, which considers, among other points, the job roles and number of exposed workers, the time spent on each activity and the physical effort. If that is not enough to decide, a quantitative assessment follows using the IBUTG index (Índice de Bulbo Úmido Termômetro de Globo, known in English as the WBGT index, wet bulb globe temperature), according to NHO 06 from Fundacentro, Brazil's federal occupational safety and health research foundation. For outdoor activities without artificial heat sources, the annex allows a Fundacentro tool to estimate the IBUTG, "if available" (item 3.3.2).
• Prevention and corrective measures (item 4): detailed in the next section.
• Heat emergency procedure (item 6.1): with the means for first aid or for referring the worker, and with information for everyone involved.

Action level and exposure limit

The annex has two IBUTG tables, which vary according to the metabolic rate, that is, the physical effort of the activity. Table 1 (Quadro 1) sets the action level, and Table 2 (Quadro 2), the exposure limit. Each one triggers a set of measures:

Situation	What NR-9 requires
Action level exceeded (Table 1)	One or more measures: cool drinking water (or another suitable replacement fluid), with workers encouraged to drink it; heavier work, above 414 W, preferably at the coolest times of day, if this does not create additional risks
Exposure limit exceeded (Table 2)	One or more corrective measures: adjust processes and routines; alternate hotter tasks with others involving less exposure; provide access to cooler places, including natural ones, for thermal recovery breaks in activities in open areas far from buildings
Limit exceeded with risk of heat strain	The PCMSO (NR-07) must provide for medical assessments, complementary tests and physiological monitoring, when necessary
Exposure above the action level	Consider worker acclimatization, described in the PCMSO

The PCMSO is the Occupational Health Medical Control Program (Programa de Controle Médico de Saúde Ocupacional) required by NR-07.

Two points deserve attention. First, the standard says that a risk of heat strain, with the possibility of serious injury, is established when the measures in item 4 are not adopted or are not sufficient (item 4.2.3.1). Second, the limits only apply to workers found fit in the NR-07 medical assessment and wearing clothing that does not increase the IBUTG, according to the annex's own corrections. That is why the type of uniform also counts.

NR-21: shelter and protection against excessive sun

NR-21, on open-air work, is short and direct. It requires shelters, "even if rustic", that protect workers from the weather (item 21.1), and special measures against excessive sun exposure and heat, among other factors (item 21.2).

In security and front-desk contracts, this often depends on the client, who owns the guardhouse, the gate cover or the rest area. That is why the topic needs to be part of the conversation with the client, not just of the service provider's PGR.

NR-24: cool water in sufficient quantity from January

Today, NR-24 requires drinking water at all workplaces and bans shared cups (item 24.9.1). Water must be supplied through drinking fountains, at a minimum ratio of one for every group of 50 workers or fraction thereof, or through another system offering the same conditions (item 24.9.1.1).

Portaria MTE 1.590, of September 8, 2026, rewrote these items, effective January 12, 2027. From that date:

• water must be available "in sufficient quantity" and be drinkable, filtered and cool, with the ban on shared cups maintained;
• when drinking fountains or an equivalent system cannot be used, water must be supplied in individual, hermetically sealed portable containers, which must be stored in a suitable place throughout the shift (item 24.9.1.1.1).

For people working at sites without a drinking fountain, such as isolated guardhouses, outdoor patrols and mobile cleaning crews, the change calls for planning: who provides the bottle or the jug, where it is kept during the shift and how the water stays cool.

What about the hazard pay premium?

These are different rules. NR-9 deals with prevention. Unhealthy work due to heat, which entitles workers to the hazard pay premium (adicional de insalubridade), is covered by Annex 3 of NR-15, and that annex says it does not apply to open-air activities without an artificial heat source (item 1.1.1). It applies to indoor settings or those with an artificial heat source, such as industrial kitchens and areas near furnaces or engines.

In practice, not being entitled to the premium does not exempt the company from prevention. A doorman who spends the day in the sun may not receive hazard pay for heat, but the company is still required to assess the exposure in the PGR and to adopt the measures in NR-9, NR-21 and NR-24. Specific premium cases should go through the legal team and a technical report.

The impact on HR and payroll

In operations with client sites, heat affects several routines at once:

• Schedules: concentrating the heaviest tasks at the coolest times and rotating between sunny and shaded posts requires coverage planning, especially with lunch reliefs and relief staff.
• Breaks: thermal recovery breaks, when adopted, must be built into the site routine so the post is not left uncovered.
• Uniforms: the fabric and color of the uniform count in the assessment. Reviewing the summer kit can be a simple, inexpensive measure.
• Onboarding and training: people who start in the middle of summer, such as year-end temporary staff, may not yet be acclimatized, a point the annex requires companies to consider.
• Medical notes and incidents: feeling unwell, fainting or sunstroke at the post should be recorded and analyzed, because they show where the measures are not working.
• Client contract: shelter, shade, a water point and a break area often depend on the client's facilities. It is worth formalizing what each party is responsible for.

What to do now

• Ask the SESMT (the company's in-house occupational safety and health service) or your OSH consultancy to review the PGR and confirm that heat is assessed at outdoor sites
• Map the posts exposed to the sun: guardhouses, entrances, parking lots, outdoor cleaning areas and patrols
• Ensure cool drinking water at every post and plan portable containers where there is no drinking fountain, with the January 12, 2027 rule in mind
• Review schedules to concentrate heavy tasks at the coolest times and plan breaks and post rotation when indicated
• Brief teams on warning signs and on whom to tell, and train site leaders in the emergency procedure
• Review uniforms and talk to clients about shelter, shade and water points at the posts
• Record heat-related incidents and medical notes to fix what is not working

Frequently asked questions

Does NR-9 apply to people who work outdoors?

Yes. Annex III of NR-9 applies wherever there is occupational exposure to heat, without excluding open-air work, and even provides for a Fundacentro tool to estimate the IBUTG in outdoor settings without artificial heat sources. NR-21 also requires shelter and measures against excessive sun exposure.

Are people who work in the sun entitled to hazard pay for heat?

Under Annex 3 of NR-15, unhealthy work due to heat does not apply to open-air activities without an artificial heat source. This does not exempt the company from the prevention required by NR-9. Each case should be assessed with a technical report and the legal team.

What changes for water from January 12, 2027?

The new wording of NR-24, introduced by Portaria MTE 1.590/2026, requires drinkable, filtered and cool water in sufficient quantity at all workplaces, with no shared cups. Where there is no drinking fountain or equivalent system, water must come in individual, hermetically sealed portable containers, stored in a suitable place during the shift.

Conclusion

The forecast of a hotter summer does not create new obligations, but it makes existing ones urgent. NR-9 calls for heat assessment, guidance, prevention measures and an emergency procedure; NR-21 calls for shelter and protection against the sun; and NR-24 will require cool water in sufficient quantity from January. For companies with outdoor sites, the work runs through the PGR, the schedules and the conversation with each client. For another area of occupational safety at client sites, see PPE control in outsourcing: what NR-6 requires and how to avoid liability.

Want to organize schedules, site checklists, incidents and training for people who work in the sun in one system? Talk to the Tirvu team and see TIRVU+ working in your own operation, with schedules, checklists with photo evidence, a digital incident log and uniform control.

Sources

• Agência Gov, the federal government's news agency: Brazil should face high temperatures and heat waves in the coming months (Oct 29, 2026)
• MTE: NR-09, text updated in 2026, with Annex III (Heat)
• MTE: NR-15, Annex 3, tolerance limits for heat exposure
• MTE: NR-21, open-air work
• MTE: NR-24, text updated with Portaria MTE 1.590/2026

This content is for informational purposes only and does not replace specialized legal advice.