OSHA Heat Regulations in Outdoor and Indoor Work Settings

Current OSHA Guidelines for Heat Safety

Before the new OSHA Heat Regulations are finalized, OSHA has already established several existing guidelines and practices for heat safety, such as the following:

General Duty Clause

The General Duty Clause is a key component of the Occupational Safety and Health Act (OSH Act) of 1970. Often applied when there are no specific industry standards for heat exposure and heat stress, it requires employers to provide and maintain a workplace clear of recognized hazards that can cause injury, illness, and death at all times.

National Emphasis Program (NEP)

The NEP is an OSHA initiative targeting specific hazards or high-risk industries to enhance worker safety and health. It focuses on areas with significant risks, such as heat stress or chemical exposure.

NIOSH’s Heat Standard

The National Institute for Occupational Safety and Health (NIOSH) Recommended Heat Standard provides criteria for heat-related illnesses and injury prevention for workers. Revised in 2016, this standard provides guidelines on how to keep track of environmental conditions using the Wet Bulb Globe Temperature (WBGT) and the Recommended Exposure Limits (RELs) based them.

Existing Recommendations

Before the proposed regulations, OSHA suggested basic measures to prevent heat illness, such as the following:

• Rest Breaks: Provide paid breaks every two hours and monitor for heat illness.
• Hydration Access: Ensure continuous access to drinking water.
• Shade and Cooling Areas: Offer shaded or air-conditioned areas for breaks.
• Acclimatization: Gradually expose new or returning workers to high heat.

State-Specific Heat Standards

State-specific heat standards are regulations individual states implement to address heat-related safety in the workplace. These often go beyond federal guidelines to provide additional protections for workers. Some states with heat protection standards include:

1. Cal/OSHA Heat Illness Prevention Standard: California’s regulations are comprehensive, requiring employers to provide potable water, shade, rest breaks over 80°F (~26.67°C), heat illness prevention training, and acclimatization for new or returning workers. Industries that must comply include:
   • Agriculture and Landscaping
   • Construction
   • Oil and gas extraction  
   • Transportation
   • Delivery or distribution of agricultural products or heavy materials
2. Washington’s Outdoor Heat Exposure Rule: These apply specifically to outdoor workers and include requirements for:
   • Access to drinking water and shaded areas when temperatures exceed 100°F (~37.78°C).
   • Mandatory training on heat illness recognition and prevention.
3. Minnesota Indoor Heat Regulations: Minnesota’s key provisions for indoor workplace’s hot and cold temperatures include regulations that trigger indoor temperatures exceeding certain levels. When assessing indoor climate health risks, these terms are used:
   • Heavy Work: 350+ kcal/hr (e.g., heavy lifting)
   • Moderate Work: 200-350 kcal/hr (e.g., walking, lifting)
   • Light Work: Up to 200 kcal/hr (e.g., sitting)
4. Oregon Heat Illness Prevention Standard: Oregon OSHA has implemented new regulations to shield workers from the dangers of high heat and wildfire smoke.
5. Colorado Agricultural Labor Conditions Rules: Colorado has adopted regulations on agricultural workers established under Senate Bill 21-087 to improve their labor rights and responsibilities.

New Proposed OSHA Heat Rule

In August 2024, OSHA announced a key proposal for rules on preventing heat injury and illness, a big step towards a national heat safety standard called the Heat Injury and Illness Prevention in Outdoor and Indoor Work Settings rule. This standard applies to all employers doing outdoor and indoor work in general industry, construction, maritime, and agriculture, where OSHA has authority.

The rule applies to all workers exposed to high heat, regardless of occupation, industry, or workplace setting. However, exemptions include teleworkers, those consistently working in cool environments, individuals in emergency response roles, and anyone exposed to heat either briefly or below the 80°F (~26.67°C) threshold.

This groundbreaking change is yet to be finalized after 120 days of feedback submission, following the publication in the Federal Register. This new rule aims to do the following:

Address Climate Change in Occupational Settings

OSHA aims to address the growing concern of heat stress in workplaces systematically. Between 2011 and 2022, an average of 40 US workers died annually from environmental heat exposure, while 3,389 experienced heat-related injuries and illnesses that required days away from work each year.

Establish Federal Heat Standard

With a federal heat standard, OSHA will require employers to take action when the risk of heat-related illness is present in their workplaces. The proposed rule identifies high temperatures as a workplace hazard that requires employers to act, including engineering and administrative interventions.

New OSHA Heat Regulations Key Requirements

The expected proposed rule requires employers to do the following:

Create a Heat Injury and Illness Prevention Plan (HIIPP)

Employers must develop a HIIPP tailored to their specific workplace conditions. Since each workplace environment may pose distinct risks related to heat exposure, the HIPP should incorporate procedures for both indoor and outdoor settings.

Identify and Assess Heat Hazards

Employers must monitor the heat index or WBGT to assess heat exposure risks. They must track local heat index forecasts for outdoor worksites, while indoor worksites require a heat hazard monitoring plan.

Monitor the Initial Heat Trigger

At a heat index of 80°F (~26.67°C), employers must:

• Ensure cool, accessible drinking water for all (at least 1 quart per hour per worker)
• Allow paid rest breaks as needed
• Provide shaded or air-conditioned break areas (outdoors or indoors)
• Implement an acclimatization plan for new and returning employees
• Communicate regularly with employees about heat conditions

Monitor the High Heat Trigger

For heat index values at or above 90°F (~32.22°C), employers must:

• Provide a minimum of 15-minute paid rest breaks every two hours
• Implement an observation system to check for signs of heat illness
• Maintain two-way communication with workers who are working alone
• Issue heat hazard alerts emphasizing the importance of hydration, rest breaks, and emergency procedures

Create an Acclimatization Plan

Employers must follow an acclimatization process during the first week of work for new employees or workers returning after an absence of more than 14 days. This includes gradually increasing heat exposure or incorporating high-heat safety measures from the outset.

Ensure Emergency Preparedness

Employers must develop site-specific heat illness prevention plans. To include in one are clear procedures for managing heat-related emergencies and providing immediate assistance to workers showing signs of heat illness.

Conduct Environmental Monitoring Tasks

Employers must monitor heat in both outdoor and indoor worksites, ideally by tracking local heat index forecasts or using on-site monitoring devices like Internet-of-Things (IoT) sensors for outdoor sites. Indoor sites require a more detailed approach, where employers must identify work areas with potential heat exposure and create a monitoring plan.

Technology for Heat Safety Compliance

As the proposed rule requires employers to monitor and track heat conditions, technological advancements have made it easier for businesses to comply with these rules. Here are the technologies that can assist employers in monitoring heat exposure:

IoT Sensors

IoT sensors provide real-time data on environmental conditions, including temperature, humidity, and air quality. They have alarm systems that alert employers when the heat index reaches a specific threshold.

Wearables

Wearable technology can monitor workers’ core body temperature and alert them when they are at risk of heat-related illness. They also provide employers with real-time data on their employees’ health status.

Mobile Apps

Mobile apps can help employers track outdoor worksites’ local heat index forecasts and provide real-time alerts. They can also be used to conduct safety inspections in tandem with checklists  and communicate important information.