Heat stress can cause severe illness and death. Proper precautions and training are needed to work safely in hot conditions. Employers should develop a heat illness prevention program that includes providing shade and water, training workers on heat illness signs and first aid, and allowing new workers to gradually adjust to hot environments over 10-14 days. Recognizing and promptly treating heat rash, cramps, exhaustion and stroke is critical. Workers should drink water regularly, avoid caffeine and alcohol, and rest in shade to prevent heat-related illness.
2. Severe Weather Fatalities “… heat is by far the number one killer of all weather events…” Courtesy National Weather Service Forecast Office
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21. WBGTI Heat related illness includes: heat rash, cramps, exhaustion and stroke. These illnesses are a real danger to people not accustomed to the stress of hot weather exercise. The Wet-Bulb Globe Temperature Index (WBGTI) takes into account four variables: air temperature, humidity, radiant heat and air movement. This reading gives a more accurate measurement of heat stress than any one reading alone.
22. Heat Stress Flag Colors Black - Wet Bulb Globe Thermometer (WBGT) index of 90 o or Above . Physical training and strenuous exercise must be suspended for all personnel. (excludes operational commitment not for training purposes) . A “20-minute work/ 10- minute rest” cycle may be utilized, as well as employee rotation. Above 89 88 – 89.9 85 - 87.9 82-84.9 Red - WBGT index of 88 – 89.9 0 . St renuous exercise must be curtailed for all personnel with less than 12 weeks training in hot weather. Yellow - WBGT index of 85 – 87.9 o . Strenuous exercise and activity must be curtailed for new and unacclimatized personnel during the first 3 weeks of heat exposure. Outdoor classes in the sun must be avoided. Green - WBGT index of 82 – 84.9 o . Discretion is required in planning heavy exercise for unacclimatized personnel. This is a marginal heat stress limit for all personnel. (numbers are Wet Bulb Globe Temperature Index- not temperature ) Wearing body armor or NBC protective uniforms adds approximately 10 points to measured WBGT. Limits of exposure should be adjusted accordingly.
23. Heat Stress Illnesses Heat Rash Causes- Heat rash normally happens most often in hot, humid conditions, particularly wearing heavy clothing and with excessive sweating. Fair skinned individuals are more prone to develop heat rash. Symptoms : Interferes with sleep and results in decreased deficiency and cumulative fatigue. Treatment: Treated by keeping skin dry, use of cooled sleeping quarters, calamine lotion .
24. Heat Stress Illnesses Heat Cramps Causes It occurs when large volumes of water are consumed without adequate salt replacement. Symptoms : Severe pain and cramps in legs and abdomen, fainting or dizziness, weakness, profuse sweating and headaches. Treatment: Increase fluid intake, increase salt intake, rest and move to a cool place. Usually resolves after an electrolyte beverage.
25. Heat Stress Illnesses Heat Exhaustion Causes Occurs when the heart and vascular system do not respond properly to high temperatures, and the mechanisms our body uses to cool itself fails Symptoms : Headache, nausea, fatigue, dizziness, skin is cool and pale, pupils become dilated. Victim is usually conscious but may faint, has a core temperature of over 102. Treatment: Get to the shade, cool off, increase fluids, cold wet towels or ice, fan, elevate legs above heart, loosen clothing, don’t give any liquids containing alcohol or caffeine, may need IV. If condition worsens seek medical attention immediately. If left untreated Heat Exhaustion can lead to HEATSTROKE.
Although rarely recognized, heat is by far the number one killer of all weather events. Over the last ten years, heat has averaged nearly 200 fatalities a year, with flash flooding being second to heat with 90 fatalities a year. In 1995 alone, there were over 1021 heat related fatalities. Extreme heat affects all, but the elderly, poor, infants and those who work outside during the summer are the most likely to succumb to the heat.
A new, unacclimatized, 55 year old laborer collapsed due to high heat while working outdoors hand excavating footings on a hot and smoky day. The laborer was transported to a Medical Center, found to have a temperature of 107*F, diagnosed with heat stroke, admitted, but progressed into multisystem organ failure. The laborer died nine days later on 20 Jul 08. The employer was cited General for failure to include all required procedures in the written heat illness prevention procedures and Serious, Accident Related, for failure to train a new, unacclimatized employee on the employer's heat illness prevention procedures.
The sandbags are used to support the installation of a 36" diameter natural gas pipeline. The ambient temperature at the time of the incident was approximately 110 degrees. The crew started work at 0700 and were to quit at 1700. The crew had water and ice to drink and shade was provided by their shuttle bus at the worksite. The worker went down at approximately 1530 and was non-responsive to verbal instructions and physical stimuli and displayed signs of heat stress and/or possible heart attack. The worker was air-evacuated to a Medical Center and passed away the following morning at approximately 0930.
Victim was one of two fire instructors conducting class in fire fighting techniques for a community college. Afternoon portion of class included donning turnout gear and SCBA for various demonstrations and practical application. Outside temperature high of 97 F. At the end of class, both instructors were refilling tanker truck with water from a hydrant. Victim collapsed. Other instructor started CPR and contacted 911. EMS responded and victim was transported to hospital, where he was pronounced dead due to heat exhaustion.
Section 5(a)(1) of the Occupational Safety and Health Act of 1970: The employer did not furnish employment and a place of employment which were free from recognized hazards that were causing or likely to cause death or serious physical harm to employees in that: Employees were exposed to excessive environmental heat while performing framing work on a single family residential construction site. Employees were exposed to a heat index of approximately 102 degrees Fahrenheit, as reported on 08/03/2006, by the National Oceanic and Atmospheric Administration weather station in Melbourne Florida. Such exposures may lead to the development of serious heat induced illness such as heat exhaustion and/or heat stroke. a) For employees performing framing and other related construction activities where the heat index is approximately 102 degree Fahrenheit, the employer failed to asheat-load to which they may be exposed and failed to develop and implement a heat stress program designed to protect employees from that exposure. The estimated work-load for these employees puts them in the moderate workload category as correlated with the guidelines established by the American Conference of Governmental Industrial Hygienist (ACGIH) and the National Institute for Occupational Safety and Health (NIOSH). Means of feasible abatement include but may not be limited to: 1. Develop and implement a written heat stress program which includes, at a minimum, the following items: a) Establish provisions for a work/rest regimen to reduce the work exposure time to excessive environmental heat. b) A training program informing employees about the effects, signs and symptomsand prevention of heat induced illness and to include specific instructions and warnings concerning the effects of heat stress. c) An acclimation policy for new employees to adjust to the working conditions. d) Develop and implement a pre-employment medical questionnaire designed to determine employees' fitness to work in hot environments. e) Provide protective covers or personal protective clothing to protect employees from the heat. f) Provide ample supplies of cool drinking water.
Employers may begin the shift with smaller quantities of water if they have effective procedures for replenishment during the shift as needed to allow employees to drink one quart or more per hour. The frequent drinking of water, as described in (e), shall be encouraged.
Except for employers in the agricultural industry, cooling measures other than shade (e.g., use of misting machines) may be provided in lieu of shade if the employer can demonstrate that these measures are at least as effective as shade in allowing employees to cool.
Employee training. Training in the following topics shall be provided to all supervisory and non-supervisory employees. (A) The environmental and personal risk factors for heat illness; (B) The employer's procedures for complying with the requirements of this standard; (C) The importance of frequent consumption of small quantities of water, up to 4 cups per hour, when the work environment is hot and employees are likely to be sweating more than usual in the performance of their duties; (D) The importance of acclimatization; (E) The different types of heat illness and the common signs and symptoms of heat illness; (F) The importance to employees of immediately reporting to the employer, directly or through the employee's supervisor, symptoms or signs of heat illness in themselves, or in co-workers; (G) The employer's procedures for responding to symptoms of possible heat illness, including how emergency medical services will be provided should they become necessary; (H) The employer's procedures for contacting emergency medical services, and if necessary, for transporting employees to a point where they can be reached by an emergency medical service provider; (I) The employer's procedures for ensuring that, in the event of an emergency, clear and precise directions to the work site can and will be provided as needed to emergency responders. (2) Supervisor training. Prior to assignment to supervision of employees working in the heat, training on the following topics shall be provided: (A) The information required to be provided by section (e)(1) above. (B) The procedures the supervisor is to follow to implement the applicable provisions in this section. (C) The procedures the supervisor is to follow when an employee exhibits symptoms consistent with possible heat illness, including emergency response procedures. (3) The employer's procedures required by subsections (e)(1)(B), (G), (H), and (I) shall be in writing and shall be made available to employees and to representatives of the Division upon request.
Heat stress factors include ambient air temperature, relative humidity, heat radiation (from sun, earth, machinery and from your body), air movement and surface temperatures. The “Heat Index” was implemented in 1984 to combine the ambient air temperature with relative humidity to determine an apparent temperature of what the air actually feels like. Don’t judge conditions by temperature alone: relative humidity plays a big part in heat stress. In conditions of high humidity, evaporation of sweat, a cooling process, is inhibited.
Heat Exhaustion starts with the accumulation of large quantities of blood in the skin in the body’s attempt to increase it’s cooling efficiency. This is normally due to temperature conditions the individual is not used to. There is a loss of circulating blood volume in the body which decreases the blood supply to the brain, increasing the likelihood of fainting.
The underlying cause of heat stroke is connected to the sudden inability to dissipate body heat through perspiration. This accounts for the excessive rise in body temperature and it’s the high fever which can cause permanent damage to internal organs, and can lead to death. When someone passes out from heat stroke, his or her brain is being cooked just as the colorless part of an egg turns white when it hits the griddle. Any cold liquid should be used to cool the victim. Once revived, the victim should be watched for more than an hour as his temperature can start to rise to high levels again.
