Heat rules in New Zealand: no set temperature, a duty to manage heat
What WorkSafe New Zealand says about working in extreme heat: the Health and Safety at Work Act sets no safe temperature, the business must manage the risk so far as reasonably practicable, and the controls and warning signs its guides list.
Checked against the sources at the bottom of this page on October 8, 2026. Rules, fees and pay change: the source has the last word.
This page reports what the official source says. It is not legal advice: ask the office named here. It restates three WorkSafe New Zealand publications, all dated December 2019, as read on October 8, 2026: the good practice guidelines Working safely in extreme temperatures, and the fact sheets Working in extreme heat for businesses and for workers. WorkSafe publishes them under a Creative Commons Attribution-Non-commercial 3.0 NZ licence, and the wording here is our own summary. The comparison of every place is on the heat rules overview.
No minimum or maximum temperature
The guidelines say the Health and Safety at Work Act 2015 does not state minimum or maximum safe temperatures for work. They give the reason that no safe air temperature can be set alone, because the effect depends on humidity, sun or other radiant heat, air movement, work rate, clothing and protective equipment, and personal health. They give the example that an air temperature safe in low humidity, light work and light clothing may be a risk with high humidity, hard work and heavy protective equipment. They say it is up to the person conducting a business or undertaking to do a workplace risk assessment, with workers consulted, and decide a safe working range for that place. Humidity over 80 percent is described as slowing the evaporation of sweat.
The business fact sheet puts the legal duty this way: the business must make sure, so far as is reasonably practicable, that workers are not put at risk while working in extreme heat. The guidelines list "any outdoor work during summer in hot regions" among the work that may have extremely hot conditions, and name forestry as an example of work that may have extremely cold conditions, especially in winter.
Controls the guides list
| Type | Examples as the guides word them |
|---|---|
| Engineering | Remove the source of heat if reasonably practicable; shade from the sun while working outdoors; mechanical aids to reduce the physical demands |
| Scheduling | High activity tasks in cooler parts of the day, such as early morning; for outdoor work, where reasonably practicable, avoid working when the sun is high; plan high activity tasks for cooler times of the year |
| Exposure | Rotate hot or physically demanding tasks among workers; sun hats, long-sleeved clothing and sunscreen; extra breaks away from the heat, with a work-rest schedule discussed with workers; rest areas out of the sun for outdoor work |
| Monitoring | Regular monitoring of workers for signs of heat-related illness; a buddy system, with workers in pairs watching each other |
| Protective equipment | Used only after the other reasonably practicable controls; light, breathable material so workers can sweat freely |
Worker fact sheet: symptoms and stopping work
The worker fact sheet says workers should stop work if they think the work environment has become unsafe, or they notice signs of heat-related illness or injury in themselves or a workmate, and tell a supervisor. It sets out four conditions. Heat rash shows as small, red, itchy bumps. Heat cramps are muscle pains and spasms, usually in the abdomen, arms or legs. Heat exhaustion has heavy sweating, paleness, muscle cramps, weakness, dizziness, vomiting, headache, a fast and weak pulse and shallow breathing, and its treatment starts with stopping work immediately and moving to a cool place. Heat stroke is a high body temperature, above 39.4 degrees Celsius, with confusion, disorientation, unconsciousness, red hot dry skin and a throbbing headache, and the sheet says to call 111 for immediate medical assistance. It also says workers have the right to be consulted before any health monitoring starts.
Sources
- WorkSafe New Zealand, Working safely in extreme temperatures, good practice guidelines, December 2019, read October 8, 2026
- WorkSafe New Zealand, Working in extreme heat: a guide for businesses, December 2019, read October 8, 2026
- WorkSafe New Zealand, Working in extreme heat: a guide for workers, December 2019, read October 8, 2026