Environmental Health and Safety (EH&S) has the primary responsibility for assisting departments in implementation of this policy through training and consultation.

EH&S is available to monitor the heat exposure of individual jobs and make recommendations to reduce heat stress risk. If employees must work for extended periods (i.e. more than 1 continuous hour/day) outdoors during hot weather or above the threshold limit value (TLV) for heat exposure, EH&S will arrange for the training of supervisors. This training will include the signs and symptoms of heat stress and preventive measures that can be taken.

Departments have the primary responsibility for providing training, sources of drinking water, and supporting supervisors in adjusted work schedules to reduce heat exposure during heat events.

Departments are responsible for ensuring employees who are working in hot environments take necessary precautions as outlined in the section entitled Control of Heat Stress.

Supervisors/Principal Investigators have the primary responsibility for the implementation of the Heat Stress Prevention Program in their work area. The supervisor has ultimate responsibility for the safety of the employees.  This includes evaluation of the work to be performed, providing ready access to drinking water or electrolyte replacement drinks, ensuring workers are familiar with the signs and symptoms of heat related illnesses, allow for acclimatization of workers in hot environments, adoption of work rest regimes and scheduling of work to reduce heat stresses as appropriate and providing training for employees.

Employees have the primary responsibility for working in accordance with the provisions of this policy.

Employees are responsible for attending training and following the instructions given. They are also responsible for monitoring themselves for signs and symptoms of heat stress.

The human body regulates high temperatures by two primary mechanisms; blood flow and sweating. Blood is circulated to the skin, increasing the skin temperature and allowing the body to give off the excess heat through the skin. Sweating occurs when the body senses the heat loss due to increased blood circulation is not enough to cool the body. Evaporation of the sweat cools the skin and eliminates large quantities of heat from the body. If the body is unable to release excess heat, it will store it. When this happens, the body’s core temperature rises and the heart rate increases. If the body continues to store heat, the person may begin to have difficulty concentrating, may become irritable and lose the desire to drink. The next stage is often fainting which would signal a medical emergency. Listed in Table 1 are the common heat disorders with the accompanying symptoms and appropriate first aid measures.

Table 1 – Heat Disorders

DISORDER	CAUSE	SIGNS & SYMPTOMS	TREATMENT
Heat Cramps	Heavy sweating Loss of salt	Painful spasms of arms, legs and abdomen Sudden onset Hot, moist skin	Drink water Massage cramped area Rest
Heat Exhaustion	Dehydration Non-acclimatized	Heavy sweating Intense thirst Pale, moist, cool skin Rapid pulse Fatigue, weakness Fainting, collapse	Move to shade or an air- conditioned space Rest, lying down, legs elevated Loosen clothing Drink water
Heat Stroke	Excessive exposure to hot environments Body’s system of temp. regulation fails Body temp. rises   to critical levels	High body temperature Lack of sweating Hot, red, dry skin Rapid pulse Chills Difficulty breathing Disoriented Weakness Unconsciousness	MEDICAL EMERGENCY Call for emergency help Immerse person in water Massage body with ice

Work being done in non-air-conditioned indoor spaces may be monitored by an industrial hygienist or technician from EH&S. This monitoring will give a wet bulb globe temperature (WBGT) reading that can be used to assess the heat illness risk of the job. Employees identified as working in a high-risk area will need to follow the guidelines in Table 2 and the section Control of Heat Stress. Employees who are working outdoors or in non-air-conditioned space should pay attention to the temperature, humidity and heat stress indices. When the

heat stress index, as defined in Table 3, exceeds the extreme caution level of 90 F, precautions as outlined in Table 2 and the section Control of Heat Stress should be followed. If employees are wearing protective clothing such as welding leathers or tyvek for asbestos or agricultural work, precautions as outlined in Table 2 and the section Control of Heat Stress should be followed at a heat index in excess of 88 F.

If the heat stress index exceeds 120 F, or 118 F for workers with protective clothing, work in a heat stress environment must stop. If it is imperative that work gets done, contact EH&S for additional assistance. Historical data obtained throughout the state from the Florida Automated Weather Network (FAWN) indicates that this heat stress index was not exceeded during the summer of 1998.

Table 2 – Guidelines for Heat Exposure Limits

Always monitor signs and symptoms of heat-stressed workers. Discontinue any activity for a person when:

• Sustained heart rate greater than 160 beats per minute for those under 35 and 140 for those 35 and over.
• There are complaints of sudden and severe fatigue, nausea, dizziness, lightheadedness, or fainting.
• There are periods of inexplicable irritability, malaise or flu-like symptoms.
• Sweating stops and the skin becomes hot and dry.

*Apparent temperature, Heat Stress Index (HSI): A measure of how hot it really feels in degrees Fahrenheit when relative humidity is factored with the actual air temperature. This chart has been adapted from the National Weather Service’s “heat index” and an adjustment has been made with the apparent temperature categories to match more closely working in full sunshine. This guideline should be followed for employees not wearing protective clothing.

Employees who work in hot environments will receive training yearly regarding heat disorders, and their recognition, prevention and treatment. Training for jobs that are seasonal will be done prior to the hot season. New employees will receive training prior to working in a hot work environment.

The following guidelines should be followed to prevent heat-related disorders.

American Conference of Governmental Industrial Hygienists. TLVs and BEIs. 1999

U.S. Environmental Protection Agency. A Guide to Heat Stress in Agriculture. Publication number EPA-750-b-92-001. May 1993

U.S. Department of Health and Human Services, National Institute for Occupational Safety and Health. Criteria for a Recommended Standard. Occupational Exposure to Hot Environments. Publication number 86-113.1986

U.S. Department of Labor, Occupational Safety and Health Administration, Instruction TED 1.15, OSHA Technical Manual, Section II: Chapter 4, Heat Stress. September 22, 1995