Most heat-related injuries do not happen during heatwaves. The International Labour Organization found that eight in ten heat-related occupational injuries occur outside heatwave periods. They happen on ordinary hot afternoons, in ordinary shifts, when nobody has raised an alarm.
For leadership teams, that finding reframes heat from a seasonal welfare issue into a year-round operational risk. A loading dock in Dammam or a steel mill floor in East Java exposes workers to heat for much of the year. The consequences show up in injuries, error rates, absence and, increasingly, in how regulators and international clients judge an employer.
Both Saudi Arabia and Indonesia regulate heat at work, in different ways. This piece explains what heat stress is, what each regime requires, and how to monitor and document heat risk in a way that withstands inspection.
What is heat stress and why is it a compliance issue?
Heat stress occurs when the body cannot shed heat fast enough to keep its core temperature safe. It depends on more than the thermometer: humidity, radiant heat from roofs and machinery, airflow, physical workload and clothing all contribute.
That is why temperature alone misleads. A humid warehouse at 33°C with no airflow can be more dangerous than a dry, breezy yard at 38°C. Safety teams therefore use combined measures such as the WBGT index, which accounts for humidity and radiant heat as well as air temperature.
From discomfort to danger
Heat stress begins with fatigue, thirst and poor concentration. It can progress to heat exhaustion, with heavy sweating, dizziness and nausea. At its most severe, heat stroke shuts down the body's ability to cool itself and can kill within hours.
The commercial effect arrives earlier. A worker affected by heat makes more mistakes, reacts more slowly and takes more shortcuts. A forklift operator in a hot, poorly ventilated aisle becomes a collision risk long before anyone notices signs of illness. Error rates and near misses tend to climb with the temperature.
New workers face the highest risk. The body typically needs one to two weeks to acclimatise. Staff returning from leave, or arriving from cooler regions, need a gradual build-up of exposure rather than a full shift on day one.
The warning signs are easy to miss in a busy operation. Watch for workers who stop sweating, become confused, stumble or slur their speech. Any of these needs immediate first aid and medical help, not a short break.
Why regulators treat heat stress as a safety duty
The ILO estimates that excessive heat causes about 23 million occupational injuries and nearly 19,000 deaths a year. It also reports that the Arab states have one of the highest shares of workers exposed to excessive heat.
Those numbers explain why heat stress now sits inside occupational safety law rather than general welfare guidance. Employers must assess the risk, control it and evidence that their controls work.
The economic case is just as direct. The same ILO report estimates that better prevention could save up to $361 billion globally. For an individual employer, that saving shows up as fewer injuries, fewer lost shifts and steadier output through the hot months.
Saudi Arabia's midday work ban
Saudi Arabia's main lever is a seasonal restriction on outdoor work in direct sun.
Dates, hours and scope
The Ministry of Human Resources and Social Development prohibits work under direct sunlight between 12pm and 3pm. The restriction runs from 15 June to 15 September. The 2026 ban applies to private-sector establishments, and violations carry penalties.
The ban covers outdoor work in direct sun. Work indoors, in shade or in cooled spaces can continue. Employers need to reorganise shifts so that no one performs exposed outdoor tasks during the restricted window.
For logistics and construction operators, this has a planning cost. Yard work, loading and outdoor maintenance move to early morning or evening. Shift plans, contractor schedules and delivery windows all need to reflect the change, and clients need to accept it.
The ban also creates a quiet documentation duty. If an inspector visits at 1pm, you must show that no outdoor work is under way. You must also show where workers are and what they are doing instead.
The risk outside the ban window
The midday ban is necessary, but it is not a complete heat strategy. Research on Saudi outdoor workers found high heat exposure between 10am and 12pm, a period the ban does not cover.
Indoor environments carry their own risk. A warehouse with a metal roof, limited airflow and heavy manual handling can exceed safe limits even after outdoor work stops. Vehicle cabs with failing air conditioning do the same to drivers on long desert routes.
A complete Saudi heat plan therefore covers three periods. It enforces the ban during the restricted hours. It applies work-rest controls in the hours either side. It monitors indoor and in-vehicle heat throughout the year.
Indonesia: heat exposure limits under Permenaker 5/2018
Indonesia regulates heat through workplace environment standards rather than a seasonal ban.
The ISBB index
The Ministry of Manpower's Regulation No. 5 of 2018 sets limits using the ISBB index (Indeks Suhu Basah dan Bola). ISBB is Indonesia's equivalent of the WBGT heat index. The regulation's guidance links permitted heat levels to workload and to work-rest patterns.
The principle is intuitive. Light work tolerates higher ISBB values, while heavy physical work requires lower limits or more rest. Employers must measure the working environment and adjust schedules whenever readings exceed the threshold for the task.
Indonesia's humidity makes this especially relevant. High humidity slows the evaporation of sweat, so workers lose their main cooling mechanism even at moderate temperatures.
Measurement is the foundation of compliance here. You need ISBB readings for each work area, taken when heat peaks during the day. Those readings set the work-rest pattern for each task, so they must be current and on record.
Heat stress inside SMK3
Heat exposure also falls within the SMK3 safety management framework. Auditors expect measured heat data, documented controls and evidence that supervisors acted when conditions exceeded limits.
How do you monitor heat stress on site?
Under either regime, compliance depends on continuous monitoring rather than an annual measurement filed away.
Work-rest schedules
Build work-rest cycles that match the measured heat and the physical demand of each task. Rotate workers between hot and cool tasks. Place shaded or cooled rest areas close to the work, so that breaks actually happen rather than being skipped to save walking time.
Water matters as much as rest. Put drinking water within easy reach of every work zone, and encourage workers to drink before they feel thirsty.
Clothing and PPE add to the heat load. Heavy coveralls, chemical suits and full-face respirators trap heat. Where the PPE cannot be removed, shorten exposure and lengthen rest for the people wearing it.
Spotting warning signs on camera
Supervisors cannot see every worker on every shift. Cameras can. Computer vision can flag a worker who has collapsed or a person lying motionless in an active area. It can also flag an outdoor zone that is still occupied during the restricted midday window.
The same cameras can confirm that workers wear required PPE and stay out of restricted hot zones. Each alert reaches a supervisor while there is still time to intervene.
Coverage matters most at night and in remote areas, where a collapsed worker can go unnoticed for longest. Continuous review gives every zone the same attention, regardless of how many supervisors are on shift.
Documenting every intervention
Every heat-related alert should produce a record: what the system detected, who responded and what they did. Those records show an inspector, an auditor or a client that your heat stress plan works in practice, not only on paper.
Building a heat stress plan that survives an audit
A good heat stress plan fits on a few pages and connects directly to daily operations. This four-part structure is a reliable starting point.
Assess
Map every task and zone by heat exposure and workload. Include indoor areas, vehicle cabs and loading docks, not only outdoor sites. Identify the people who need acclimatisation, such as new starters and returning staff.
Record the assessment and date it. Repeat it at the start of each hot season and whenever a process, building or shift pattern changes.
Control
Set work-rest schedules, move heavy tasks to cooler hours, and provide water, shade and cooling. Enforce the midday ban in Saudi Arabia and the ISBB limits in Indonesia.
Give supervisors clear authority to stop work when conditions exceed the plan. A control that requires sign-off from head office will fail on a busy afternoon.
Monitor
Measure heat during each shift. Use camera alerts to cover the zones and shifts that supervisors cannot reach in person.
Record and review
Keep one log of measurements, alerts and interventions. Review it monthly and adjust controls where incidents or near misses cluster. Add heat checks to your site safety audit checklist, so that every audit tests the plan.
From heat policy to operational discipline
Heat stress is unusually predictable. Forecasts arrive days ahead, and the hottest zones in a facility rarely change. What fails is the link between knowing the risk and acting on it in the middle of a shift.
VISOR closes that link on the cameras you already run. It detects people down, occupied restricted zones and PPE gaps in real time, alerts the right supervisor and records every response. Core9 already monitors 130,000 square feet of warehouse space daily for one enterprise client.
QUESTIONS TO ASK YOUR LEADERSHIP TEAM
• Can we prove, for any day last summer, that no one worked in direct sun between 12pm and 3pm?
• Which of our indoor sites and vehicle routes exceed safe heat limits outside the ban window?
• Do supervisors have the authority to stop work when heat limits are breached?
• How quickly would we know if a worker collapsed in a remote zone at night?
If you want to see how continuous monitoring would support your heat stress plan, book a 15-minute call with Core9.
See this against your own company’s data.
