If your business sends people to work outdoors in Singapore, the heat is no longer just a comfort issue. Since 2023, the Ministry of Manpower has imposed specific, inspectable duties on employers to manage heat stress for outdoor workers, and on 28 August 2026 it added four more, effective 1 December 2026. A worker who collapses from heat injury on the job can be a compensable claim under the Work Injury Compensation Act. For a construction firm, a landscaping contractor, a cleaning company, or a delivery operation, that is two exposures stacked on top of each other: a regulatory duty that can attract penalties if breached, and a work-injury liability that your WICA insurance has to absorb.

The Answer in 60 Seconds Singapore's heat stress framework for outdoor workers, revised by MOM on 6 September 2024, sets out required measures that "must be implemented" at defined Wet Bulb Globe Temperature (WBGT) bands: acclimatisation, hydration, rest under shade, WBGT monitoring, and an emergency response plan (MOM, Revised framework to guide employers and protect outdoor workers against heat stress, 6 September 2024). On 28 August 2026 MOM enhanced the framework: four practices that were recommended become mandatory on 1 December 2026, namely a heat stress training programme for exposed workers, cool drinking water near work areas, cold water, ice packs or water spray on standby for emergencies, and suitable clothing against heat stress (MOM press release, 28 August 2026). These measures give specific content to the general duty an employer already owes under section 12 of the Workplace Safety and Health Act 2006, which requires an employer to take, so far as is reasonably practicable, measures necessary to ensure the safety and health of employees at work (Workplace Safety and Health Act 2006, Part 4).

Separately, heat injury can be a compensable work injury. Under section 7 of the Work Injury Compensation Act 2019, an employer is liable to pay compensation where personal injury is caused to an employee "by an accident arising out of and in the course of" employment (Work Injury Compensation Act 2019, Part 2). A heat stroke or heat exhaustion suffered while doing outdoor work in the WBGT conditions MOM warns about can fall within that wording. Because WICA insurance is mandatory under section 24 unless the employees fall in a class the WIC (Insurance) Regulations exclude, such as those of retailers and hotel-keepers, the cost ordinarily sits with your insurer (WICA 2019, Part 3), but only if the policy is in force and the claim is properly handled.

The Sourced Detail

What MOM actually requires for heat stress

The current rules trace back to October 2023, when MOM introduced enhanced measures to reduce heat stress for outdoor workers (MOM, Enhanced Measures to Reduce Heat Stress for Outdoor Workers, 24 October 2023). On 6 September 2024 MOM published a revised framework that aligns the employer's obligations with the three-tier Heat Stress Advisory used for the general population, indexed to the Wet Bulb Globe Temperature, an internationally recognised measure that combines air temperature, humidity, wind speed and solar radiation (MOM, Revised framework, 6 September 2024).

The framework draws a hard line between required measures, which MOM says "must be implemented," and recommended practices, which employers "consider." The required measures, escalating across three WBGT bands (below 31 degrees Celsius, 31 to less than 33, and 33 and above), include:

  • Acclimatisation. Gradually increase daily heat exposure over at least 7 days for workers new to Singapore or returning from leave of more than a week.
  • Hydration. Ensure workers rehydrate regularly, and at least hourly at the two higher bands. Providing a cool drinking water supply near work areas is a recommended practice until 1 December 2026, when it becomes a requirement.
  • Rest and shade. Ensure workers get adequate rest under shade. At a WBGT of 32 degrees and above, provide hourly rest breaks of at least 10 minutes for heavy physical work; at 33 degrees and above MOM lists 15-minute hourly breaks, and longer rest as WBGT rises, as recommended practice rather than as a marked requirement.
  • WBGT monitoring. Monitor WBGT every hour during work hours. On-site WBGT meters are required for construction sites with a contract sum of S$5 million or more, shipyards and the process industry (MOM infographic); other workplaces can refer to the National Environment Agency's myENV app.
  • Emergency response. Establish an emergency response plan and implement reporting procedures.

(All from the MOM revised framework, 6 September 2024 and its one-page framework for outdoor workers, which marks the required items in bold; MOM's updated infographic shows the same table as it stands from 1 December 2026.) MOM has stated it will conduct workplace inspections to ensure the required measures are implemented (same 2024 source). For an SME, the practical reading is simple: the bolded "must" items are not advisory. They are the standard an inspector will measure you against.

What changes on 1 December 2026

On 28 August 2026 MOM enhanced the framework and gave employers three months to comply. Four practices that MOM says were "previously recommended under the Heat Stress Framework for Outdoor Work" become mandatory requirements on 1 December 2026 (MOM, 28 August 2026). From that date employers of outdoor workers are required to:

  • Train. Establish a heat stress training programme for workers exposed to heat.
  • Supply water. Provide a cool drinking water supply near work areas.
  • Stand by to cool. Ensure cold water, ice packs or water spray are on standby for emergency response.
  • Clothe. Provide suitable clothing that mitigates or protects workers from excessive heat stress.

MOM states that the four "have been widely adopted by employers" and that it is making them mandatory "to ensure consistent implementation across the industry" (same source). The release adds one new recommended practice, that rest areas under shade be well ventilated and well insulated or cooled, and states that the enhancements complement the existing requirements on WBGT monitoring, hydration, rest breaks under shade, acclimatisation and emergency response planning (same source). The Minister of State for Manpower put the timetable plainly: "I encourage employers to use the next three months to review their workplace practices and put the necessary measures in place before the enhancements take effect on 1 December 2026" (same source). MOM's one-page infographic sets all of the measures against the three WBGT bands and marks each requirement as such (Heat Stress Measures for Outdoor Work, MOM infographic).

For an SME the change is administrative before it is physical. Water, ice packs and suitable clothing are purchases. A training programme is a record: who was trained, on what, and when. After 1 December 2026 an inspector who asks for that record is asking about a requirement, and if the matter reaches a prosecution, section 47 of the WSH Act, discussed below, makes it yours to prove that it was not reasonably practicable to do more than you did (WSHA 2006, section 47).

How this sits inside the WSH Act

The heat framework does not exist in a vacuum. It puts concrete content onto a duty that already binds every employer under the Workplace Safety and Health Act 2006. Section 12, in Part 4 of the Act, requires an employer to take, so far as is reasonably practicable, the measures necessary to ensure the safety and health of its employees at work, including providing a safe work environment and the information, instruction and supervision necessary for safety (WSHA 2006, Part 4 General Duties of Persons at Workplaces).

Two features of the Act matter for heat stress. First, the standard is "so far as is reasonably practicable," and section 47 places the onus of proving what was reasonably practicable on the person who owed the duty (WSHA 2006, section 47). If a worker suffers heat stroke and MOM asks why the required acclimatisation, rest breaks, or WBGT monitoring were not in place, it is the employer who must show that compliance was not reasonably practicable. The published framework makes that a high bar, because MOM has already defined what reasonable practice looks like, and from 1 December 2026 the definition includes training, water, emergency cooling and clothing.

Second, breach carries penalties. Section 50 sets out general penalties for breaches of the Act, and section 48 extends liability from a body corporate to its officers: when a company commits an offence, each officer is also guilty unless the officer proves that the offence was committed without his or her consent or connivance and that he or she exercised all due diligence to prevent it (WSHA 2006, Part 10 Offences, Penalties and Proceedings). A heat injury that triggers an investigation is not only a WICA claim. It can be a WSH enforcement matter as well.

Note that the duties now reach beyond the traditional employer. Section 12A of the Act imposes duties on platform operators (WSHA 2006, Part 4), which is directly relevant to delivery work performed in the open air through digital platforms. The heat exposure for outdoor delivery is no longer outside the WSH net.

Where heat injury meets WICA

The second exposure is compensation. The Work Injury Compensation Act 2019 governs no-fault compensation for work injuries in Singapore. Section 7, in Part 2, states that where personal injury is caused to an employee "by an accident arising out of and in the course of the employee's employment," the employer is liable to pay compensation under the Act (WICA 2019, Part 2 Compensation for Work Injury).

A heat stroke or serious heat exhaustion suffered by a worker laying paving in direct sun, or clearing drains in high-WBGT conditions, can fit that wording: it is a sudden injury to the body, it happened during work, and it arose from the heat exposure inherent in that outdoor work. WICA also defines "injury" to include an occupational disease, and item 4 of the Act's Second Schedule names "Diseases caused by excessive heat" for "any occupation involving exposure to excessive heat" (WICA 2019, definitions, Part 2 and the Second Schedule). The mechanism by which a particular heat-related claim is assessed, whether as an accident or under the occupational-disease route, is a determination for MOM and the attending doctors on the facts, not something an employer should pre-judge. What an SME needs to absorb is that the claim has a credible path into WICA, and that the cost lands on the employer's WICA insurer first.

That insurance is not optional. Section 24 of the Act, in Part 3, requires an employer to insure and maintain insurance "against all liabilities that the employer may incur under this Act in respect of every employee", subject to the excluded classes of employee that the regulations prescribe (WICA 2019, Part 3 Work Injury Compensation Insurance). Outdoor construction, landscaping, cleaning and delivery crews are overwhelmingly manual employees, so the WICA insurance obligation is squarely engaged. For the underpinning of that mandatory-insurance rule, see our explainer on WICA Section 24 and the mandatory insurance provision.

Why the two exposures interact

Here is the part SMEs miss. The same heat injury can simultaneously trigger a WICA claim and a WSH investigation, and the two are not insulated from each other. WICA compensation is no-fault, so the worker is compensated regardless of who was at fault. But if the MOM investigation concludes that the employer failed the required heat-stress measures, the employer faces a separate WSH enforcement exposure under section 50 (WSHA 2006, Part 10). Designated WIC insurers must also share claims information with MOM, which is shared with other designated insurers; MOM says this "enables insurers to price premiums more accurately, and safer companies will pay less premium" (MOM, Summary of Regulatory Regime for WIC Insurers under WICA 2019). Separately, from 1 June 2024 MOM raised the maximum fine for breaches of the WSH subsidiary legislation that could result in serious harm from S$20,000 to S$50,000 (see our note on the 2024 WSH fine increase).

So heat stress is not one risk. It can be a WICA claim, a potential WSH penalty and a factor in your WICA premium, all running off a single incident.

Common Mistakes

  1. Treating the heat framework as a guideline rather than a duty. The bolded items in the MOM framework are required, not recommended. "We told the men to drink water" is not the same as documented acclimatisation, scheduled rest breaks and hourly WBGT monitoring.
  2. Treating the four new measures as still optional after 1 December 2026. Training, water supply, emergency cooling and clothing were, in MOM's words, "previously recommended" practices under the framework. From 1 December 2026 they are requirements, and MOM gave three months' notice so that the date is not a surprise.
  3. Assuming heat injury is never a work injury. Because heat is "natural," some employers assume it cannot be a compensable accident. The WICA test is whether the injury was caused by an accident arising out of and in the course of employment, not whether the cause was man-made.
  4. Leaving delivery and gig crews out of the analysis. Section 12A now puts duties on platform operators (WSHA 2006, section 12A). Outdoor delivery work is inside the WSH framework, not outside it.
  5. Carrying no WBGT data and no training record. If you cannot show what the WBGT was, what measures you applied and who was trained, the section 47 onus to prove what was reasonably practicable falls on you with nothing to point to.
  6. Forgetting the insurance link at renewal. A heat-injury claim plus a WSH finding does not just cost the claim. It can move your WICA premium and your loss record for years.
  7. Confusing WICA with full liability cover. WICA compensation is capped and scheduled. A worker who pursues a common-law claim for negligence is a separate exposure that WICA insurance alone does not answer.

What This Means for Your Business

If you run outdoor labour in Singapore, treat heat stress as a named hazard in your risk assessment, the same way you treat work at height or confined spaces, and put 1 December 2026 in the diary now.

For a construction SME. If any of your sites has a contract sum of S$5 million or more, on-site WBGT meters are a required measure, not a nice-to-have (MOM infographic). Build the hourly monitoring, the acclimatisation log for new and returning workers, the 10 minute hourly rest breaks at WBGT 32 and above, and the 15 minute breaks MOM recommends at 33 and above into your site safety plan, and keep the records. Before 1 December 2026, add the heat stress training programme, the drinking water points, the emergency cooling kit and the clothing to the same plan. When MOM inspects, the documentation is your defence.

For a landscaping or cleaning contractor. Your crews move between sites and are not on the list of workplaces that must carry on-site WBGT meters. Use the NEA myENV app readings, schedule heavy work to cooler parts of the day where feasible, and make sure every supervisor knows the emergency response steps for a worker showing signs of heat illness. Identify vulnerable workers, including older workers, those returning from long leave, and anyone unacclimatised, and adjust their deployment. A vehicle-based crew carries its cold water, ice packs or water spray with it from 1 December 2026.

For a delivery or platform operation. The platform-operator duties under section 12A (WSHA 2006, Part 4) mean you cannot treat riders as wholly outside the WSH framework. Hydration access, sensible scheduling around peak-heat periods, and a clear channel to report heat illness are the baseline, and where you employ riders directly, a heat stress training programme is a requirement from 1 December 2026.

For all of the above. Confirm your WICA insurance is in force and correctly covers every manual worker, including subcontracted and casual labour where you are the responsible employer. Then map the gap between WICA's scheduled compensation and a potential common-law negligence claim, because a heat-injury case where the employer ignored the required measures is exactly the kind of fact pattern that invites a common-law action.

Questions to Ask Your Adviser

  1. Does my current WICA policy cover every manual worker I deploy outdoors, including subcontracted, casual, and temporary crews?
  2. Heat injury aside, does my cover respond to a common-law negligence claim from an injured worker, or only to scheduled WICA compensation?
  3. How would a heat-injury claim, combined with an adverse MOM finding on the required heat-stress measures, affect my renewal pricing?
  4. If a worker suffers heat stroke, what is the notification sequence: when do I report to MOM, and when do I notify the insurer?
  5. Do I have any coverage that responds to the cost of a WSH enforcement action, separate from the compensation itself?
  6. For my platform or delivery operation, how does my insurance treat workers covered by the platform-operator duties in the WSH Act?
  7. Where are the gaps between what WICA pays and what a serious, permanent heat-injury disability would actually cost the business?
  8. Does anything in my policy or my renewal declaration refer to compliance with MOM's heat stress framework, and does the 1 December 2026 change affect it?

Related Information

Published 31 May 2026. Source verified 11 September 2026.