4 heat-stress measures that become mandatory on 1 December 2026
Training, cool water, emergency cooling and suitable clothing move from recommended to required. Here is what that means for your worksite.
On 28 August 2026, the Ministry of Manpower (MOM) announced changes to its heat-stress framework for outdoor work. Four practices that were only recommended until now will become requirements from 1 December 2026.
Employers have a three-month window to get ready. Here is what is changing, what stays the same, and how to prepare your worksite in time.
The four measures becoming mandatory
From 1 December 2026, employers and occupiers with outdoor workers must have these in place.
1. Heat-stress training
Workers exposed to heat need to be trained. As a minimum, they should know how to spot the signs of heat illness, why water and rest matter, and what to do in an emergency. Supervisors need to know how the WBGT bands change the rest and water schedule.
To prepare: set up a short training session, run it for everyone who works outdoors, and keep a record of who attended and when.
2. Cool drinking water near the work
Workers must have cool drinking water close to where they actually work. MOM's FAQ describes this as a short, convenient distance, generally no more than a 3 to 5 minute walk.
To prepare: plan water stations for each work area, not one cooler at the site entrance. Work out how much water a shift needs and who refills it.
3. Emergency cooling on standby
Cold water, ice packs or water spray must be ready for an emergency, so a worker showing signs of heat illness can be cooled quickly. Instant chemical cold packs can help, but they do not replace these.
To prepare: keep emergency cooling supplies in a known spot, make sure they are cold, and check them as part of the daily routine.
4. Suitable clothing
Workers must have clothing that helps reduce heat stress, for example loose, light-coloured and breathable workwear, while still meeting the PPE each task requires.
To prepare: review current uniforms and PPE against the heat, and replace what traps heat where the task allows.
A new recommendation: better rest areas
Alongside the four requirements, MOM now recommends that shaded rest areas be well ventilated, insulated or cooled. A tarp in direct sun gives shade, but it can still be very hot underneath. Fans, air coolers or an insulated shelter make the rest break do its job.
What stays the same
The existing measures continue to apply:
- WBGT monitoring every hour during outdoor work
- Regular hydration throughout the shift
- Rest breaks in the shade, which get longer at higher WBGT levels
- Heat acclimatisation for new and returning workers
- An emergency response plan for heat illness
If you want the detail for each WBGT level, read our guide MOM heat stress measures: what to do at each WBGT level.
Before and after 1 December
| Practice | Until 30 Nov 2026 | From 1 Dec 2026 |
|---|---|---|
| Heat-stress training | Recommended | Required |
| Cool drinking water near work areas | Recommended | Required |
| Cold water, ice packs or water spray for emergencies | Recommended | Required |
| Suitable clothing for the heat | Recommended | Required |
| Ventilated, insulated or cooled rest areas | Not specified | Recommended |
A checklist for the next few weeks
- Walk the site and note each work area, how far it is from water and shade, and where an emergency cooling kit would go.
- Book the training and plan how you will record attendance.
- Order supplies early: water coolers, cooler boxes, ice packs, rest shelters and workwear. Demand will rise as the deadline approaches.
- Assign owners: who checks the WBGT, who refills water, who checks the emergency kit.
- Review it again once the site layout or crew size changes.
HeatAware puts these pieces together in one kit, sized to your crew and work areas. Get your kit sized in three steps and see which of the 17 check points your site already meets.
Frequently asked questions
Who has to comply?
Employers and occupiers with workers doing outdoor work that exposes them to heat, mainly work in the open without permanent shade.
When do the new requirements start?
1 December 2026. MOM announced them on 28 August 2026, giving employers about three months to prepare.
Will MOM help companies prepare?
MOM has said it will carry out outreach and engagement to help employers put the enhanced measures in place.
This article is general guidance based on MOM's press release of 28 August 2026 and its Heat Stress Measures for Outdoor Work. Always check the latest official guidance and your own risk assessment.