With apologies to Glenn Frey, the “Heat Is On” as summer is in full blast in western Colorado. On May 31, Grand Junction recorded a record high of 95 degrees. And Grand Junction hit 100 degrees twice before summer officially started this year. How does our hot weather affect employers?

In July 2024, the Occupational Safety and Health Administration issued proposed regulations aimed at protecting workers from heat-related illnesses and injuries. The new regulations impose significant measures to protect employees from extreme heat and will require considerable changes to some employers’ safety protocols.

While the new regulations were proposed last year, OSHA just completed an informal public hearing on the proposed Heat Injury and Illness Prevention in Outdoor and Indoor Work Settings rule that concluded on July 2, 2025. The rule’s future adoption is not certain. The new administration could decide to withdraw the rule, or the rule could run afoul of recent Supreme Court cases limiting federal agency actions.

But now is the time for employers to prepare for new standards, and of course, it is never wrong to further employee safety in the workplace.

For years, OSHA relied upon its General Duty Clause, which simply requires employers to maintain a workplace free from recognized hazards likely to cause death or serious harm. The new rule would impose specific heat-mitigation requirements on all employers conducting outdoor and indoor work in all general industry, construction, maritime and agriculture sectors where OSHA has jurisdiction.

This coverage is very broad but not without limits. OSHA has no jurisdiction over public employers, so the new rule would not apply to government employers. The proposed rule also exempts “sedentary” indoor workers, employees who work at indoor sites kept below 80 degrees, emergency-response activities, remote employees and short-term exposure to heat.

The proposed standard first would require covered employers to develop and implement a worksite heat injury and illness prevention plan (HIIPP) with site-specific information to evaluate and control heat hazards in their workplace. Second, the new rule would require employers to identify heat hazards at worksites.

For indoor worksites, employers would be required to identify work areas that pose risks of hazardous heat exposure and develop a monitoring plan. Further, the employer must seek employee input in developing the plan.

For outdoor sites, the employer must monitor heat conditions by tracking local heat index forecasts or measuring heat index or wet bulb globe temperature (WBGT).

The new rule would require employers to take action upon two specific heat levels as measured by the heat index or the WGBT. The heat index takes into account temperature and humidity. The WGBT is a more accurate measure of heat risk, taking into account ambient temperature, humidity, radiant heat from sunlight or artificial heat sources, and air movement. WGBT measuring devices that meet OSHA’s standards are expensive. While the rule gives employers the discretion to choose its monitoring method, it is possible that OSHA will consider the method the employer used, especially in serious investigations.

Monitoring the heat index is much simpler. The employer can monitor the heat index by consulting the National Weather Service website. In fact, OSHA already offers the NIOSH/OSHA Heat App for mobile devices.

The Initial Heat Trigger for employer action is reached when the heat index reaches 80 degrees or a WGBT temperature equal to the NIOSH Recommended Action Limit. Employer responses to this trigger include providing employees:

1. Cool drinking water.
2. Break areas with cooling measures.
3. Indoor work area controls.
4. Acclimatization protocols for new and returning unacclimatized employees.
5. Paid rest breaks if needed to prevent overheating.
6. Regular and effective two-way communication.

The High Heat Trigger occurs when the heat index reaches 90 degrees or a WGBT equal to the NIOSH Recommended Exposure Limit. This trigger would require employers to provide:

1. Mandatory rest breaks of 15 minutes at least every two hours (unpaid meal breaks may count as rest breaks).
2. Observation for signs and symptoms of heat-related illness.
3. A hazard alert to remind employees of key parts of the HIIPP.
4. Warning signs at indoor work areas with ambient temperatures that regularly exceed 120 degrees.

Finally, the new rule requires employers to implement heat safety training for employees and supervisors about the symptoms and dangers of heat-related illnesses and the importance of preventive measures. Also, the employer requires employers to implement acclimatization plans for new and returning workers that would include gradually increasing workloads and heat exposure time to build employees’ heat resistance.

Interestingly, the Colorado Legislature this year introduced HB 25-1286 concerning protecting workers from exposure to extreme temperatures. The Colorado bill would have applied to government employers and entities that contract with five or more independent contractors in the state each year. The bill was postponed indefinitely in committee.

Employers who have not implemented measures to protect employees from heat-related illnesses and injuries should do so immediately. OSHA offers advice for working in heat environment on its heat exposure webpage, available at www.osha.gov/heat-exposure.

Employers Council members may access numerous resources for managing work heat environments. Consulting and Enterprise members may speak in person with the Employers Council’s human resources professionals and employment attorneys for assistance in formulating legally defensible and practical heat-risk measures.