Heat Stress

John Newquist

June 2009

Severe Weather FatalitiesSevere Weather Fatalities

“…heat is by far the number one killer of all weather events…”

Courtesy National Weather Service Forecast Office

News

• CAL-OSHA labor officials said Thursday, May 19, 2009 they have shut down five more farm labor contractors whose crews were found laboring in triple-digit heat with no shade, not enough water and no training in safety and emergency response.

Fatalities

• 7/10/08• A new, unacclimatized, 55

year old laborer collapsed while working outdoors hand excavating footings on a hot and smoky day.

• 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.

Fatalities

• On 7/10/08 • 37 year old male that was

loading boxes of grapes • He was taken by

ambulance to Community Hospital and was treated for Heat Stroke with a core body temperature of 108 degrees.

• He died on 07/31/08 at 3:25 p.m. from heat stroke.

Fatalities

• 7/15/08• A mechanic for the

employer suffered fatal injuries from heat stroke while working in the service bay area of the truck maintenance shop.

Fatalities• 06/30/2008 • One worker unloading 40

pound sandbags to support the installation of a 36" diameter natural gas pipeline.

• Temperature was approximately 110 degrees.

• The worker went down in the late afternoon and was non-responsive.

• The worker was air-evacuated to a Medical Center and passed away the following morning at approximately 0930.

Fatalities

• 6/6/08• Instructors conducting class in

fire fighting techniques. Afternoon portion of class included donning turnout gear and SCBA for various demonstrations and practical application.

• Outside temperature high of 97 F.

• Victim collapsed during truck water filling and was transported to hospital, where he was pronounced dead due to heat exhaustion.

Risk Factors

• Age• Weight• Fitness• Acclimatization• Use of alcohol and

drugs• Hypertension• Clothing worn

Guidance

• OSHA has no specific heat illness guidance. They would use the General Duty Clause of the OSHA Act. (See next)

• NIOSH has guidance

• Cal-Osha has regulations that cover this issue

Sample General Duty Clause Violation

• 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 symptoms and 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.

Cal OSHA rules

• Provision of water. • Employees shall have

access to potable drinking water.

• Where it is not plumbed or otherwise continuously supplied, it shall be provided in sufficient quantity at the beginning of the work shift to provide one quart per employee per hour for drinking for the entire shift.

CAL-OSHA rules• Access to shade.• Employees suffering from heat

illness or believing a preventative recovery period is needed, shall be provided access to an area with shade that is either open to the air or provided with ventilation or cooling for a period of no less than five minutes.

• Such access to shade shall be permitted at all times.

CAL-OSHA Rules• Employee training. Training in the following topics shall be provided

to all supervisory and non-supervisory employees.• The environmental and personal risk factors for heat illness;• The employer's procedures for complying with the requirements of

this standard;• 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;

• The importance of acclimatization;• The different types of heat illness and the common signs and

symptoms of heat illness;• 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;

CAL-OSHA Rules

• Employee training continued• The employer's procedures for responding to symptoms

of possible heat illness, including how emergency medical services will be provided should they become necessary;

• 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;

• 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.

CAL-OSHA rules• Supervisor training. • Prior to assignment to supervision of employees working in the heat,

training on the following topics shall be provided:• The heat information required to be provided to employees• The procedures the supervisor is to follow to implement the

applicable provisions in this section.• The procedures the supervisor is to follow when an employee

exhibits symptoms consistent with possible heat illness, including emergency response procedures.

• The employer's procedures shall be in writing and shall be made available to employees and to representatives of Cal-Osha upon request.

NIOSH Recommendations

• Schedule maintenance and repair jobs in hot areas for cooler months.

• Schedule hot jobs for the cooler part of the day. • Acclimatize workers by exposing them for

progressively longer periods to hot work environments.

• Reduce the physical demands of workers. • Use relief workers or assign extra workers for

physically demanding jobs.

NIOSH Recommendations• Provide cool water or liquids to workers. • Avoid drinks with caffeine, alcohol, or large amounts of sugar. • Provide rest periods with water breaks. • Provide cool areas for use during break periods. • Monitor workers who are at risk of heat stress. • Provide heat stress training that includes information about: • Worker risk• Prevention • Symptoms • The importance of monitoring yourself and coworkers for symptoms • Treatment • Personal protective equipment

NIOSH to Employees• Wear light-colored, loose-fitting, breathable clothing such as cotton. • Avoid non-breathing synthetic clothing. • Gradually build up to heavy work. • Schedule heavy work during the coolest parts of day. • Take more breaks in extreme heat and humidity. • Take breaks in the shade or a cool area when possible. • Drink water frequently. Drink enough water that you never become

thirsty. • Avoid drinks with caffeine, alcohol, and large amounts of sugar. • Be aware that protective clothing or personal protective equipment

may increase the risk of heat stress. • Monitor your physical condition and that of your coworkers.

Water LossWater Loss

Normally, with light activity, your body loses 2 to 3 quarts of water daily. In a hot weather environment, you loose 6 to 8 quarts of sweat which is critical to your bodies cooling. Your thirst mechanism is not sensitive enough to be an accurate indicator of your body’s needs. Encourage workers to drink water-about a cup of water every 15 to 20 minutes, even if they are not thirsty. Avoid alcohol, caffeine and soft drinks.

WBGTIWBGTI

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.

Heat Stress Heat Stress Flag ColorsFlag Colors

Black- Wet Bulb Globe Thermometer (WBGT) index of 90o 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 – 89.90. Strenuous exercise must be curtailed for all personnel with less than 12 weeks training in hot weather.

YellowYellow-- WBGT index of 85 – 87.9o. 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 – 84.9o. 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.

Heat Stress Illnesses Heat Stress Illnesses Heat RashHeat 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.

Heat Stress Illnesses Heat Stress Illnesses Heat CrampsHeat 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.

Heat Stress Illnesses Heat Stress Illnesses Heat ExhaustionHeat 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.

Heat Stress Illnesses Heat Stress Illnesses Heat StrokeHeat Stroke

Causes- Heat stroke is a medical emergency and a life threatening condition. It is caused by the failure of the heat-regulating mechanisms of the body, due to high heat and humidity.

Symptoms: Headache, nausea, dizziness, skin is red, dry and very hot (sweating has ceased). Pulse is strong and rapid, small pupils, high fever 105. May be disorientated, lose consciousness, possible convulsions.

Treatment: Remove to cooler location, loosen clothing, immerse in cool water, wrap in wet sheets, cold compresses to the

head, neck and groin. Place ice pack behind neck - under armsSEEK MEDICAL ATTENTION IMMEDIATELY. DO NOT give medication to lower fever, DO NOT use an alcohol rub.

• Underestimate the seriousness of heat illness

• Give the victim medications to reduce fever

• Give the victim liquids that contain alcohol or caffeine

• Give anything by mouth if HEAT STROKE is suspected

Heat Basics

• If muscles are being used for physical labor, less blood is available to flow to the skin and release heat

• If body can’t dispose of excess heat, it will store it. When this happens the body’s core temperature rises and the heart rate increases.

Heat Basic

• Don’t use the feeling of thirst as an indicator that you need water.

• You can deplete as much as 30% of your body’s water before you feel thirsty. Drink plenty of water before, during and after time spent in the heat.

• Individuals vary in their tolerance to heat stress conditions

Prevention• Spending time in air-

conditioned environments• Increase nonalcoholic/• Non-caffeinated fluid

intake• Monitor urine output

More• Persons working either

indoors or outdoors in high temperatures should take special precautions including allowing 10 -14 days to acclimate to high temperatures

• Salt tablets are not recommended and may be hazardous to many people

Summary

• Develop a heat illness program

• Provide cooling or shaded area

• Plenty of water

• Training

• Treatment of heat illnesses

• Acclimatize workers

Questions?