Working in Extreme Heat Regulations in Ontario 2024

With the arrival of summer, the threat of heat stress becomes a critical concern, especially in physically demanding industries.

Recent statistics from the Workplace Safety and Insurance Board highlight a troubling trend, with 350 lost-time claims related to heat stress occurring between 2006 and 2015 among construction workers alone.

In response to this growing issue, the Ontario Ministry of Labour, Immigration, Training and Skills Development (MLITSD) is taking significant steps to enhance worker safety with new legislation aimed at combating heat-related illnesses.

At Rescue7, as experts in health and safety training, we are closely monitoring these developments to ensure that our clients are well-prepared and fully compliant with the upcoming changes.

The Current Landscape of Heat Stress Regulation

Under the existing framework of the Occupational Health and Safety Act (OHSA), employers and supervisors in Ontario are mandated to take all reasonable precautions to ensure worker safety.

This includes the formulation of policies to manage risks in both hot and cold environments.

However, these regulations provide only a vague outline without specific guidelines or standards for managing heat stress, nor do they establish a clear methodology for assessing heat stress risks.

The Need for Specific Heat Stress Regulations

The absence of detailed standards in current legislation has left many employers without the necessary tools to effectively safeguard their workers against heat-related risks.

This gap in the regulatory framework not only jeopardizes worker health but also places businesses at risk of non-compliance penalties and operational disruptions.

Ontario’s Progressive Step Forward

In recognition of these challenges and the escalating risks posed by climate change, the MLITSD is proposing a pioneering Heat Stress Regulation, slated for implementation before the summer of 2024.

This proposal represents a proactive approach to worker safety, reflecting a broader understanding of the implications of global warming on occupational health.

Key Features of the New Proposal

Establishment of Heat Stress Exposure Limits: The new regulation is set to introduce exposure limits for heat stress based on methodologies endorsed by the American Conference of Governmental Industrial Hygienists (ACGIH). These limits will provide a concrete benchmark for employers to measure and manage heat exposure in the workplace.

Adoption of Alternative Assessment Methods: Flexibility in compliance is offered through the allowance of alternative methods for assessing heat stress, accommodating a variety of workplace environments and operational models.

Implementation of a Hierarchy of Controls: Employers will be required to implement specific control measures to mitigate heat stress. This structured approach prioritizes the elimination or reduction of hazards before relying on personal protective equipment or administrative controls.

Educational Requirements for Workers: Critical to the success of any safety initiative, the proposal mandates that employers must educate their workforce on recognizing symptoms of heat-related illnesses and the protective measures available to them.

Comprehensive Protection Measures: Employers will need to take all necessary precautions to prevent hazardous thermal conditions that could lead to heat-related illnesses or allow a worker’s core temperature to exceed 38°C (100°F).

Implications for Businesses

The introduction of these regulations necessitates that businesses, particularly those in high-risk industries such as construction, manufacturing, and agriculture, undertake a thorough review of their current safety policies and procedures.

Companies like Rescue7 play a pivotal role in this transition, offering tailored training and compliance solutions to help businesses adapt effectively to these new requirements.

You can find out more about our Health & Safety Trainings here


The upcoming Heat Stress Regulation in Ontario is a testament to the province’s commitment to enhancing worker safety in light of changing environmental conditions. As we anticipate the official roll-out of the regulation, businesses must begin preparing now to meet these new standards.

At Rescue7, we are dedicated to supporting our clients through this change, ensuring they not only comply with new legal requirements but also foster a safer and healthier workplace for all employees.

In the end, these measures are not just regulatory requirements; they represent a fundamental shift towards a more proactive and preventive approach to occupational health and safety in the face of global climate challenges.