OSHA Heat Regulation

OSHA Proposes Increased Heat Regulations

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OSHA Identifies Heat Related Injuries Or Death As The Leading Cause Of Death Among All Hazardous Weather Conditions In The United States

By Robert G. Brody and William C. Collins

Early last month, the Occupational Safety and Health Administration (OSHA) proposed the Heat Injury and Illness Prevention in Outdoor and Indoor Work Settings rule. The aim is to curb heat related injuries or death which OSHA identifies as “the leading cause of death among all hazardous weather conditions in the United States.” The proposal places new responsibilities on employers: establishing heat thresholds, developing Heat Injury and Illness Prevention Plans, regularly monitoring temperatures, and establishing safety measures when heat thresholds are met. This rule is yet to be finalized however, it is a sign of what’s to come.

The standard applies to all employers except for the following:

  • Work activities for which there is no reasonable expectation of exposure at or above the initial heat trigger.
  • Short duration employee exposures at or above the initial heat trigger of 15 minutes or less in any 60-minute period.
  • Organizations whose primary function is the performance of firefighting and other certain emergency services.
  • Work activities performed in indoor work areas or vehicles where air conditioning consistently keeps the ambient temperature below 80°F.
  • Telework (work from home).
  • Sedentary work activities at indoor work areas that only involve some combination of the following: sitting, occasional standing and walking for brief periods of time, and occasional lifting of objects weighing less than 10 pounds.

Heat Thresholds

There are two heat thresholds which will trigger employer action:

  • An “initial heat trigger” means a heat index of 80°F or a wet bulb globe temperature (defined below) equal to the National Institute for Occupational Safety and Health (NIOSH) Recommended Alert Limit; and
  • A “high heat trigger” means a heat index of 90°F or a wet bulb globe temperature equal to the NIOSH Recommended Exposure Limit.

The “heat index” is calculated by measuring the ambient temperature and humidity.

Wet bulb globe temperature is a heat metric that considers ambient temperature, humidity, radiant heat from sunlight or artificial heat sources and air movement.

Employers may choose either method of measuring the temperature.

Heat Injury and Illness Prevention Plan (HIIPP) Requirements

If an employer does not fall under the exceptions, it must develop a HIIPP with the input of non-managerial employees and their representatives for occasions when the heat threshold is surpassed. This plan may vary on the worksite but must be written if the employer has more than 10 employees and use a language employees will understand. The HIIPP must contain:

  • A comprehensive list of the type of work activities covered by the HIIPP
  • Policies and procedures needed to remain compliant with the standard.
  • Identification of which heat metric the employer will use heat index or wet bulb globe temperature.
  • A plan for when the heat threshold is met.

Along with creating the HIIPP, employers must designate one or more “heat safety coordinators” responsible for implementing and monitoring the HIIPP. The HIIPP must be reviewed at least annually or whenever a heat related injury or illness results in death, days off work, medical treatment exceeding first aid, or loss of consciousness. Employers must seek input from non-managerial employees and their representatives during any reviews or updates. The definition of “representative” is not defined; if this is broadly defined, this could be a major complexity employers must face.

Identifying Heat Hazards

Employers must monitor heat conditions at outdoor work areas by:

  • Monitoring temperatures at a sufficient frequency; and
  • Track heat index forecasts or
  • Measure the heat index or wet bulb globe temperature at or as close as possible to the work areas.

For indoor work areas, employers must:

  • Identify work areas where there is an expectation that employees will be exposed to heat at or above the initial heat trigger; and
  • Create a monitoring plan covering each identified work area and include this work area in the HIIPP.
  • Employers must evaluate affected work areas and update their monitoring plan whenever there is a change in production processes or a substantial increase to the outdoor temperature.

The heat metric employers choose will affect the thresholds. If no heat metric is specified, the heat metric will be the heat index value.  Employers are exempt from monitoring if they assume the temperature is at or above both the initial and high heat trigger, in which case they must follow the controls below.

Control Measures When Heat Triggers are Met

When the initial heat trigger is met, employers must:

  • Provide cool accessible drinking water of sufficient quantity (1 quart per employee per hour).
  • Provide break areas at outdoor worksites with natural shade, artificial shade, or air conditioning (if in an enclosed space).
  • Provide break areas at indoor worksites with air conditioning or increased air movement, and if necessary de-humidification.
  • For indoor work areas, provide air conditioning or have increased air movement, and if necessary de-humidification. In cases of radiant heat sources, other measures must be taken (e.g., shielding/barriers and isolating heat sources).
  • Provide employees a minimum 15-minute paid rest break in break areas at least every two hours (a paid or unpaid meal break may count as a rest break).
  • Allow and encourage employees to take paid rest breaks to prevent overheating.
  • At ambient temperatures above 102° F, evaluate humidity to determine if fan use is harmful.
  • Provide acclimatization plans for new employees or employees who have been away for more than 2 weeks.
  • Maintain effective two-way communication between management and employees.
  • Implement a system to observe signs and symptoms of heat related problems (e.g., a Buddy system).

When the high heat trigger is met, employers are additionally required to:

  • Provide employees with hazard notifications prior to the work shift or upon determining the high heat trigger is met which includes: the importance of drinking water, employees right to take rest breaks, how to seek help in a heat emergency, and the location of break areas and water.
  • Place warning signs at indoor work areas with ambient temperatures exceeding 102° F.

Other Requirements

Training: all employees and supervisors expected to perform work above the heat thresholds must be trained before starting such work and annually.

 What’s Next?

The rule is yet to be published in the Federal Register. Once this happens, there will be a 120-day comment period when all members of the public may offer OSHA their opinion about the rule. Whether this rule comes to fruition may also depend on which party wins the White House. Furthermore, if finalized this rule would likely be challenged in the courts, which now have more discretion to overrule agency rules following the US Supreme court case of Loper Bright Enterprises v. Raimondo and Relentless Inc. v. Department of Commerce (overturning the Chevron deference decision).

Employers should review their heat illness prevention policies to maintain compliance with regulations.


Brody and Associates regularly advises management on complying with the latest local, state and federal employment laws.  If we can be of assistance in this area, please contact us at info@brodyandassociates.com or 203.454.0560