Policies
Heat Stress
Purpose
The purpose of this Heat Stress Policy is to protect employees from the adverse effects of heat while they are performing their job. This not only applies to employees who work outside in the sun but also to employees who work inside buildings where there is no air-conditioning and little air movement.
Responsibilities
The Division of Environmental Safety and Emergency Management will monitor heat stress levels both inside and outside at approximately 10:00 a.m. and 12:00 p.m. on days likely to cause heat stress. The Physical Plant, Public Safety, Auxiliary Services, Residence Life and the Athletic Equipment Room will be alerted to the level of heat stress following those measurements. It is the responsibility of each department to inform their supervisors who in turn inform each of their employees of the occurrence of heat stress conditions and the recommended break schedule. If a heat stress level is measured at 12 p.m. it will continue at that level until dusk.
Heat stress levels will be assessed by measuring the Wet Bulb Globe Temperature Index (WBGT) which takes into account environmental factors such as humidity, wind speed, temperature, and radiant heat. This environmental index correlates with deep body temperatures and other physiological responses to heat.
The heat stress level and corresponding recommended break schedule are listed in the following table. This break schedule is based on the 1999 American Conference of Governmental Industrial Hygienists threshold limit values.
It is the responsibility of each employee to dress properly for the heat. Natural-fiber clothing which is lightweight and loose fitting is recommended for hot days. If the work will take place outside in the sun, the clothing should be light-colored.
Guidelines
On days likely to cause heat stress, activities which cause a high metabolic workload or require working in an enclosed area should be scheduled and performed in the early part of the day. On heat stress days (WBGT reaches 82.5 o F) an employee should not be working at a high metabolic rate such as occurs with pick and shovel work. All employees should adjust their work rate to a moderate level. Walking about with moderate lifting and pushing is an example of a moderate level of activity.
Fresh water should be readily available in the work vicinity in order that the employees can frequently drink small quantities. Approximately eight (8) oz. of fresh water every twenty (20) minutes is recommended.
It has been demonstrated that areas such as stairwells and hallways can be at a higher heat stress level than outdoor areas. Air movement provided by fans can significantly lower the level of heat stress.
Recommended Break Schedule for WBGT and Workload
WBGT (o F) |
|||
Heat Stress Level |
Break Schedule |
Light Work Load |
Moderate Work Load |
--------------------- |
Continuous Work |
86 |
80 |
Level I |
15 Minute Break Every Hour |
87 |
82.5 |
Level II |
30 Minute Break Every Hour |
88.5 |
85 |
Level III |
45 Minute Break Every Hour |
90 |
88 |
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A light workload would be performing light hand or arm work.
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A moderate workload would be walking about with moderate lifting and pushing.
