Heat Stress at Work: What the Physical Agents Regulations Expect Before Summer

Summer is coming, and for South African employers the heat now comes with a legal yardstick. Since 6 September 2026 the old Environmental Regulations for Workplaces have been repealed, and the Physical Agents Regulations (PAR) 2024 set the rules for heat stress. If your people work in foundries, kitchens, bakeries, boiler rooms, farms or on construction sites, "provide water and shade" no longer covers it.

What the regulations actually set

Regulation 10 deals with heat stress and works from wet-bulb globe temperature (WBGT), the index that combines air temperature, humidity, radiant heat and air movement. The numbers to know are:

• Action level: 27°C WBGT. Once exposure reaches this level, the control and surveillance duties should be switched on.
• Occupational exposure limit: 30°C WBGT, assessed as a one-hour time-weighted average.
• Monitoring to be done to a recognised standard (SANS 7243) by a competent person, not by holding a thermometer up in the shade.

A dry-bulb reading from the wall of a factory tells you very little. A hot, humid, poorly ventilated workshop can breach the limit on a day that "only" reaches 28°C outside.

The exposure risk assessment comes first

The PAR is built around a documented exposure risk assessment, completed by a competent person before exposure begins and reviewed regularly afterwards. For heat, that means identifying which tasks and areas approach the action level, who is exposed and for how long, how heavy the work is, and what protective clothing adds to the heat load. Without this document, none of the later duties can be defended.

Controls, acclimatisation and water

Regulation 10 expects controls in a sensible order. Change the process or equipment first: alternative work methods, better machine design, maintenance, and a review of layout and ventilation. Then limit the duration of exposure through work-rest schedules. Then provide drinking water and appropriate personal protective equipment, allowing for the extra heat load some clothing creates.

The regulation also requires a heat acclimatisation programme for exposed employees. New starters, people returning from leave and everyone on the first hot days of the season are the highest-risk group. A programme that phases exposure up over several days is cheap and effective, and it is likely the kind of document an inspector will ask to see.

People, not just numbers: surveillance, training and records

Where the risk assessment shows the need, Regulation 8 requires documented medical screening and surveillance. The programme is designed by an occupational medicine practitioner (OMP) and carried out by an occupational health practitioner (OHP). Employees must be told about the hazard, the health effects (heat exhaustion, heat stroke, kidney strain) and the controls in place. Records must be kept for 40 years, and offences can attract a fine or imprisonment of up to 12 months, with a daily penalty for continuing offences. A heat-related injury or death also raises criminal negligence questions.

A practical starting checklist:

1. Map hot areas and hot tasks, including outdoor work and vehicle cabs.
2. Commission WBGT monitoring by a competent person before the peak season.
3. Write or update the heat stress exposure risk assessment.
4. Put an acclimatisation and work-rest programme in place, and train supervisors to recognise early heat illness.
5. Confirm if medical surveillance is applicable and ensure record keeping.