Purpose

Employees who are exposed to excessive heat or who work in hot environments may be at risk of heat stress. Various factors can contribute to heat stress such as air temperature, physical activity, individual susceptibility, radiant heat, humidity, air flow, and clothing type. Heat stress can result in heat stroke, heat exhaustion, heat cramps, or heat rashes.  Indiana University Environmental Health and Safety (IUEHS) has developed this program to protect employees from heat-related illnesses while at work.  

Scope

This program applies to all Indiana University employees who are exposed to or may become exposed to excessive heat during the course of their job duties.

  

Protecting employees

IUEHS has developed protective criteria for employees based upon the heat index and other measures of heat stress exposure.  The heat index combines both air temperature and relative humidity into a single index. The higher the heat index, the hotter the environment will feel, and the greater the risk that employees will experience heat-related illness.  Individual susceptibility to heat-related illness can vary widely between employees. Employees gradually acclimatize when exposed to hot conditions for several weeks. When the heat index is high, special precautions are needed to protect un-acclimatized employees while they adjust to the heat, particularly on the first few days they are exposed to hot conditions.  Supervisors should monitor employees closely for signs of heat stress during this period and they should adopt appropriate work-rest schedules for these employees, starting with longer rest periods that are reduced over a two week period.  Re-acclimatization may also be necessary when employees are away from hot conditions for a few days.

Outdoor environments

Outdoor temperatures become elevated during the summer months.  IUEHS has divided heat index levels into four bands or risk levels that require specific protective measures when working outdoors (See Appendix A).  Additional protective measures are necessary when one of the following risk factors are present:  employees must wear heavy or non-breathable protective clothing (e.g. vapor barrier coveralls), employees work in direct sunlight, employees perform tasks that generate radiant heat (e.g. welding), or when employees perform prolonged strenuous activity.  However, when a combination of these risk factors occur simultaneously, see Other environments and job tasks for additional precautions. 

Office, laboratory,  and housing environments

The temperature in offices, laboratories, and housing may become elevated when equipment malfunctions and outdoor temperatures are high. When temperatures exceed 83 degrees Fahrenheit in office, laboratory, or housing environments, employees should contact FS and/or PP immediately.  The heat index (i.e. calculated from temperature and humidity measurements) should be monitored by FS and/or PP closely during these conditions.  IUEHS has divided heat index levels into two bands or risk levels that require specific protective measures when working in an office, laboratory, or housing environment (See Appendix B).  Additional protective measures are necessary when one of the following risk factors are present:  employees must wear heavy or non-breathable protective clothing (e.g. vapor barrier coveralls), employees perform tasks that generate radiant heat (e.g. welding), and when employees perform prolonged strenuous activity.  However, when a combination of these risk factors occur simultaneously, see Other environments and job tasks for additional precautions.

Other Environments and Job Tasks

Indiana University has a very diverse set of work environments and job tasks.  If the work environment or work condition is not specifically addressed in Outdoor environments or Office, laboratory, and housing environments, or if an employee reports and/or experiences heat-related symptoms in a particular environment or during a specific job task, a Wet-Bulb Globe Temperature (WBGT)-based heat exposure assessment may be necessary to ensure safe work conditions or to identify appropriate protective measures.  If heat stress is identified as a concern by an employee or by IUEHS for a particular work environment or job task that is not addressed in Outdoor environments or Office, laboratory, and housing environments, IUEHS will perform a heat exposure assessment for that specific work environment or job task.   Utilizing the results of the heat exposure assessment and the most recent guidelines specified by the American Conference of Governmental Industrial Hygienists (ACGIH), IUEHS will provide specific recommendations and precautions for the specialized job task and/or environment.