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 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 employers "must implement" 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.) 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, the cost ordinarily sits with your insurer (WICA 2019, Part 5), but only if the policy is in force and the claim is properly handled.

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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. Provide cool or cold drinking water near work areas; at the higher bands, rehydrate workers at least hourly.
  • 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, at least 15 minutes hourly.
  • 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; other workplaces can refer to the National Environment Agency's myENV app.
  • Emergency response. Establish an emergency response plan and reporting procedures for suspected heat injury.

(All from the MOM revised framework, 6 September 2024.) MOM has stated it will conduct workplace inspections to ensure the required measures are implemented (same 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.

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.

Second, breach carries penalties. Section 50 sets out general penalties for breaches of the Act, and section 48 extends liability to bodies corporate, so a company and, in defined circumstances, its officers can be exposed where a safety failure is attributable to their consent, connivance or neglect (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, with prescribed conditions listed in a schedule to the Act (WICA 2019, definitions and Part 2). 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 5, requires an employer to maintain work injury compensation insurance for every employee, subject to the classes of employee that the regulations exclude (WICA 2019, Part 5 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, and a poor safety record feeds directly into the pricing of the WICA cover at renewal. The penalty-doubling regime that took effect in 2024 sharpened that link between safety breaches and insurance cost (see our note on WSH penalty doubling and how it drives WICA and EPL pricing).

So heat stress is not one risk. It is a WICA claim, a potential WSH penalty, and a renewal-pricing event, 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. 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 arose out of and in the course of employment, not whether the cause was man-made.
  3. Leaving delivery and gig crews out of the analysis. Section 12A now puts duties on platform operators. Outdoor delivery work is inside the WSH framework, not outside it.
  4. Carrying no WBGT data. If you cannot show what the WBGT was and what measures you applied, the section 47 onus to prove what was reasonably practicable falls on you with nothing to point to.
  5. 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.
  6. 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 may 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.

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. Build the hourly monitoring, the acclimatisation log for new and returning workers, and the 10 and 15 minute rest breaks into your site safety plan, and keep the records. When MOM inspects, the documentation is your defence.

For a landscaping or cleaning contractor. Your crews move between sites and you may not have site-specific 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.

For a delivery or platform operation. The platform-operator duties under section 12A 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.

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 section 12A platform-operator duties?
  7. Where are the gaps between what WICA pays and what a serious, permanent heat-injury disability would actually cost the business?

Related Information

Published 31 May 2026. Source verified 31 May 2026. COVA is an introducer under MAS Notice FAA-N02. We do not recommend insurance products. We provide factual information sourced from primary regulators and route you to a licensed IFA who can match a policy to your specific situation.