Prevention of Heat Stroke at Work and Heat Stress at Work Warning

By the nature of their work, construction labourers and workers are subject to extreme weather conditions, such as the heatwave in Asia in recent months.

Both the Guidance Notes on Prevention of Heat Stroke at Work; and Heat Stress at Work Warning by the Labour Department (LD) have come into effect on 15 May 2023 after being announced on 8 May 2023. Employers and employees are reminded to take appropriate measures to prevent heat stroke when working in hot weather or environments.

Read: Contractors of Construction Sites Should Be Aware of Work Safety in Times of Inclement Weather

According to the Occupational Safety and Health Ordinance, employers are required to provide or maintain a system of work that is, so far as reasonably practicable, safe and without risks to health. This includes implementing appropriate measures against heat stress at the workplace, such as the scheduling of appropriate work-rest periods.

To assist employers to fulfill their responsibilities, the guidance notes detail risk factors that should be considered when conducting heat stress risk assessments and recommended control measures.

Meanwhile, the three levels of Heat Stress at Work Warning are introduced to enhance understanding the levels of heat stress in outdoor or indoor working environments without air-conditioning. Based on the Hong Kong Heat Index, the three levels of warning are: Amber (indicating high heat stress); Red (indicating very high heat stress); and Black (indicating extremely high heat stress).

The warning message will be disseminated through mobile applications (GovHK Notifications or MyObservatory); government press releases; Hong Kong Observatory’s webpage; and mass media. Employers are also urged to not unreasonably withhold wages, attendance awards or allowances for employees who have extra rest time given under the warning.

For details of the Heat Stress at Work Warning and relevant guidance notes, please refer to the LD’s webpage ( or the Occupational Safety and Health Council’s dedicated webpage ( —Construction+ Online

Sources: The Government of the Hong Kong Special Administrative Region; Wikipedia, 2023 Asia Heatwave وان ایکس بت بت فوروارد