Heat Stress Dangers Prevention Treatment
Employee Training- OSHA Review heat-related illness signs and symptoms and site-specific precautions during daily meetings and toolbox talks. Make sure everyone is trained on: How to recognize heat-related illness How to prevent it First aid (treatment) Risk factors How to contact emergency medical services
Defining the Problem Heat disorder is a general term used to describe the stresses associated with excessive heat exposure. Heat stress is the stress incurred on the body when environmental and/or physical factors prevent the transfer of excess body heat. Metabolic rate (body heat) is the body heat generated by the body s own internal functioning. Metabolic rate increases as the workload heat exposure increases.
Fatal Numbers Far too many workers die from heat stress related events every year according to the Bureau of Labor Statistics. It CAN happen to you
United States Fatalities According to the CDC, there were 3,442 fatalities between 1999-2003 Approximate average of 690 deaths per year The largest percentage being male and the elderly Age can be a major factor
In the Workplace According to OSHA, dozens of workers die and thousands more become ill while working in extreme heat or humid conditions every year. More than 40 percent of heat-related worker deaths occur in the construction industry, but workers in every field are susceptible. There are a range of heat illnesses and they can affect anyone, regardless of age or physical condition.
The Body s Response to Heat The human body naturally tries to maintain a constant internal temperature. When the internal temperature rises, the body attempts to get rid of excess heat by: 1.Increasing blood flow to skin surface 2.Releasing sweat onto skin surface
Effects of the Body s Response Reduced blood flow to brain Reduced mental alertness and comprehension Reduced blood flow to active muscles Fatigue, loss of strength Increased sweating Slipperiness
Cooling Mechanism Failures High temperature reduces effectiveness of the cooling system High humidity reduces the evaporation rate of sweat Excessive loss of sodium Dehydration begins to take place
Cause: Excessive fluid loss Dehydration Signs & symptoms: Fatigue, weakness, dry mouth Treatment: Fluids and salt replacement
Heat Rash Cause: Inflamed skin Signs & Symptoms: Rash with pink pimples, itching, tingling Treatment: Cleanse area and dry, apply calamine or other approved lotions
Heat Cramps 1. Intermittent, involuntary spasms of larger muscles that occur in an individual who is physically active in hot weather 2. Severe Cramps, Rigid Muscles 3. Usually Begin in Hands and Feet (also legs and abdomen) 4. Profuse sweating
Heat Exhaustion 1. Fatigue, Headache, Nausea 2. Excessive Thirst 3. Cramps, Weakness 4. Confusion or Anxiety 5. Profuse Sweating 6. Cold Clammy Skin 7. Slowed or Weakened Heartbeat 8. Dizziness, Fainting, Agitation
1. Nausea, Vomiting, Headache 2. Dizziness, Vertigo 3. Hot Flushed Skin 4. Rapid Heartbeat 5. Decreased or Ceased Sweating 6. Shortness of Breath 7. Decreased or Bloody Urination 8. Increased Body Temperature- (104-106) 9. Confusion or Delirium 10.Loss of Consciousness 11.Convulsions Heat Stroke
Heat Exhaustion vs. Heat Stroke Heat Exhaustion: 1. Fatigue, Headache, Nausea 2. Excessive Thirst 3. Cramps, Weakness 4. Confusion or Anxiety 5. Profuse Sweating 6. Cold Clammy Skin 7. Slowed or Weakened Heartbeat 8. Dizziness, Fainting, Agitation *Notice the Differences in Red Heat Stroke: 1. Nausea, Vomiting, Headache 2. Dizziness, Vertigo 3. Hot Flushed Skin 4. Rapid Heartbeat 5. Decreased or Ceased Sweating 6. Shortness of Breath 7. Decreased or Bloody Urination 8. Increased Body Temperature- (104-106) 9. Confusion or Delirium 10.Loss of Consciousness 11.Convulsions
Heat Stroke vs. Heat Exhaustion The differences are notable and extremely important.
Environmental/Atmospheric Factors 1. Air Temperature 2. Humidity 3. Radiant Heat Source 4. Air Circulation
Heat Illness- Contributing Factors Some risk factors that may contribute to or accelerate Heat Illness are: Elderly and obese people are at a higher risk. Employees that have experienced a heat related event in the past. Employees that have been or are sick have a diminished tolerance and may need additional breaks. Medications, such as diuretics ( water pill ) and neuroleptics (Xanax), more Alcohol Use Heart Disease, high blood pressure, kidney or liver, respiratory problems Sweat gland problems
The Quick and the Dead If the problem isn't addressed heat cramps can quickly lead to heat exhaustion, which can easily progress to heatstroke. Heatstroke, the most serious of the three heat injuries can cause shock, brain damage, organ failure, and even death.
Are You Hydrated? If you notice your urine to be dark according to the chart, measures need to be taken to adequately increase your hydration levels.
Prevention- Proper Hydration Drink plenty of fluids: 8 ounces every 20 minutes Don t rely on your thirst Eat proper meals: several fruits and vegetables have hydrating properties Getting plenty of sleep also helps
No Caffeine Caffeine can contribute to dehydration and should be avoided while working during high or extreme temperatures.
No Alcohol Alcohol greatly increases the risk of dehydration. Either refrain from alcohol consumption or drink little during times of elevated heat dangers.
Gatorade or H2O??? Water is the recommended fluid to drink regularly and consistently. Sports drinks are recommended as a supplement to water. Sports drinks do provide possible depleted electrolytes. Do remember that some sports drinks contain high levels of sugar.
Prevention- Acclimatization Acclimatization: adjust to the heat The body takes 3-5 days to get used to the heat Be careful when returning from a change in routine: (i.e. vacation or time away from the heat) Take it slow for a few days and allow your body to adjust
Prevention- What You Wear Choose proper clothing: Wear light colors if working outside Wear lightweight/breathable material Avoid long sleeves, coveralls and jackets if possible
Work Related Factors The following factors can contribute to Heat Stress Illness and require special consideration, monitoring and precautions: Workload (amount of work) Type of work Level of physical activity Duration (amount of time) spent working Personal protective equipment and clothing Weight (heavy or non-breathable vs. breathable)
Work Activity Controls Try to schedule high burden and strenuous activities during the early hours of the morning to avoid the intense midday sun and heat. Adjust crew complements in order to allow for sufficient rest and cool down breaks. Rotate workers in extreme heat if possible. Use work/rest cycles to give your body time to recover. More controls will be listed as we go along. [See Recommended Precautions]
Find or Create a Good Place to get Out of Direct Sunlight
Cooling Down Rest in the shade when you need to cool down. When resting have a well ventilated area or have a fan blowing to circulate air. A useful tool is to pour small amounts of water on the back of the neck or apply a cool cloth to back of neck. When working indoors in extreme heat, have a cool room. Portable AC units are very helpful and effective.
Portable Cooling Options
Why Sunscreen is Important? Sunburn reduces the skin's ability to release excess heat, making the body more susceptible to heat-related illness. Wear sunscreen and use other protections from direct sunlight. Shade and hats are also important for this reason.
Nobody Knows Your Body Like You Do
Radiant Heat Radiant heat is the transfer of heat energy without direct contact. Radiant heat sources are the sun or any other object that has been heated or projects heat. Radiant heat shielding materials can be used to block/shield the heat transfer from hot surfaces by using insulation or reflective screens.
As Cool As The Other Side Of The Pillow Okay, maybe not that cool, but Cool Vests can greatly help in extreme heat environments. There are 3 preferred types of cool vests on the market: 1. Vests that utilize ice 2. Circulate a cool fluid 3. Those that use air with an in-line vortex tube.
Extremely Cool Aluminized full body suits the external aluminized material blocks and reflects the radiant heat. Circulating air suits work like the air vest with the in-line vortex except with full body coverage. Respiratory protection with in-line air cooling vortex tubes used along with an airline respirator for temperatures of 150 F or higher.
Heat Stress Plan Development When working in elevated heat stress environments a Plan should be developed. The first step in developing a Heat Stress Plan is to determine the heat stress work by identifying the work rate on the table on the next slide. Record it on a document similar to the one in this presentation:
Approximate Metabolic Work Rates Appendix A Table
Work/Rest Cycle Guidelines The following work/rest cycles are guidelines published by the American Conference of Governmental Industrial Hygienists (ACGIH). They can be modified when controls involving cooling equipment are implemented. These guidelines are no substitute for proper supervision, worker awareness and common sense. Employees exhibiting signs of heat related illness while working under these guidelines should be moved to a cool area and the work/rest cycle may be modified.
Work/Rest Cycle Recommendations- ACGIH The work/rest cycles contained in the table on the following slide can be used to determine the workload per hour of employees. To use this table, a wet bulb, dry bulb and globe temperature (WBGT) monitor will be needed. Decide upon what level of work is to be done (see Appendix A Table). Based on the workload and the WBGT reading, the percent recommended work/rest is listed. See the following slide:
Work/Rest Cycle Recommendations Work / Rest Cycles Work Load Categories Light Moderate Heavy Very Heavy 75-100% Work / 0-25% Rest 88 F WBGT 82 F WBGT NA* NA* 50-75% Work / 25-50% Rest 88 F WBGT 84 F WBGT 82 F WBGT NA* 25-50% Work / 50-75% Rest 90 F WBGT 86 F WBGT 84 F WBGT 82 F WBGT 0-25% Work / 75-100% Rest 91 F WBGT 87 F WBGT 87 F WBGT 86 F WBGT * Not available - safe limits are not defined for these categories
Heat Index Chart The table on the next slide can be used to determine the temperature and humidity in the work area. These values are based on an individual wearing the right amount and type of clothing, doing light work, with little wind. Increased workloads will result in higher values. All work in temperatures of 150 F or higher require specific respiratory protection and other control measures. Note: Exposure to direct sunlight can increase Heat Index values by up to 15 F. See the Table on the next slide:
Project Location Date Superintendent Work Scope Work Location Clothing Personal Protective Equipment (Refer to Section 5.3) Temperature Relative Humidity Heat Index (Refer to Section 6.3) Work Rate (Refer to Section 6.1 and Circle One) Light Moderate Heavy Work Rest Cycle (Refer to Section 6.2) Administrative Controls (Refer to Section 5.1) Engineering Controls (Refer to Section 5.2) Site-Specific Heat Stress Plan This plan is provided as a guide for needed information in a site-specific plan.
Wet Bulb Globe Temperature (WBGT) The WBGT takes into account the ambient temperature, the humidity and the effect of radiant heat. Globe temperature is the temperature measurement that takes the effects of radiant heat and convection (wind or a draft) into consideration. Wet bulb globe temperature (WBGT) is an index of environmental heat stresses based upon three temperature measurements (wet bulb, dry bulb and globe). WBGT measurements are in units of degrees Fahrenheit ( F). Wet bulb temperature is the temperature measure that takes into consideration the effects of water evaporation. This temperature is inversely proportional to heat exchange by evaporation. WBGT Monitor
OSHA/NIOSH Heat Safety Tool App The free App allows workers and supervisors to calculate the heat index for their worksite, and based on the heat index, displays a risk level for outdoor workers. Log on to osha.gov or visit your app store to download the app on your Smartphone. Look at the following slides for the recommendations according to the Heat Safety Tool.
Recommended Precautions When the Heat Index reaches 91-103: Moderate Risk Considerations When the Heat Index reaches 104-115: High Risk Considerations When Heat Index levels are above 116: Very High to Extreme Risk According to the OSHA/NIOSH Heat Safety Tool some Recommended Precautions are the same, but some are very different depending on the calculated risk. They are listed for each category on the App. They include the following: Condition Descriptions and Warnings Water and Shade Recommendations Emergency Planning and Response Work and Rest, and more
Recommended Precautions For All 3 Categories- Moderate, High and Very High to Extreme Risk: Adequate amounts of drinking water must be in convenient, visible locations close to the work area. Drink plenty of water, even if you re not thirsty. If in the heat less than 2 hours and involved in moderate work activities, drink 1 cup (8 oz.) of water every 15 to 20 minutes. During prolonged sweating lasting several hours, drink sports drinks containing balanced electrolytes. Generally, fluid intake should not exceed 6 cups per hour. Set up cool, shaded rest areas and schedule frequent breaks. Provide shade, hats, and sunscreen, and encourage their use.
Recommended Precautions For All 3 Categories Emergency Planning and Response: Check weather forecast regularly and make sure plans are in place before hot outdoor work begins. Make sure medical help (clinic, hospital, emergency services) is nearby if not, first aid must be performed on site. Appropriately trained personnel and adequate medical supplies need to be available. Know where you are in case you need to call 911.
Know the Difference The following slides will explain the differences in recommended precautions for High or Very High to Extreme Risk considerations as noted by OSHA/NIOSH.
Recommended Precautions When the Heat Index reaches 104-115, High Risk Considerations: Work practices considered to be High Burden should be actively managed. Those activities may include but are not limited to: Work requiring the use of FR clothing and rubber gloves and sleeves Work in confined/enclosed spaces Work taking place in direct sunlight A recommendation of a 10 minute break during every hour of work in these types of conditions should be considered.
Recommended Precautions When Heat Index levels are above 116, Very High to Extreme Risk: Reschedule all non-essential work for days when the heat index is lower. Move essential work to the coolest part of the day start earlier, split the work shift, or work evening/night shifts. Strenuous tasks and those requiring the use of heavy or non-breathable clothing or impermeable chemical protective clothing should not be conducted (if possible). If emergency or essential work must be done at this heat index, then a designated knowledgeable person should be on-site to modify work activities and set work/rest schedules. STOP WORK if protective measures are not possible. For emergency work and essential work that cannot be rescheduled, review the next slide:
Recommended Precautions When Heat Index levels are above 116, Very High to Extreme Risk: When heat index levels are above 116, management should give consideration to suspending high burden work activities. If work activities must take place in these extreme conditions, it is recommended to take a 10 minute break for every 30 minutes of work. Breaks should take place in a air-conditioned building or vehicle and employees should be closely monitored for signs and symptoms of heat illness. Establish a clear drinking schedule. Actively encourage workers to drink water often.
Recommended Precautions When Heat Index levels reach High or Very High to Extreme Risk: Acclimatize new and returning workers. These individuals are at higher risk for heat-related illness. Closely supervise unacclimated workers. Establish and follow a work/rest schedule. Take into account the level of exertion and type of personal equipment used. Supervisors should enforce rest breaks in cool, shaded areas. Remove protective clothing (if possible) while resting. Increase rest time as heat index rises or if workers show signs of heat-related illness.
Recommended Precautions When Heat Index levels reach High or Very High to Extreme Risk: Adjust work activities. Do strenuous tasks earlier in the day. Where possible, set up shade canopies over work areas. Permit only acclimatized workers to perform more strenuous tasks. Decrease the pace of strenuous job tasks. Look for other ways to adjust work activities (add more workers, rotate jobs) See very high to extreme risk precautions if working in direct sun.
When Heat Index levels reach High or Very High to Extreme Risk: If wearing heavy or non-breathable clothing or impermeable chemical protective clothing, these additional precautions are needed: Reschedule activities for when the heat index is lower (morning, evening, different day). Modify work/rest schedules to accommodate those wearing protective clothing. Physiologically monitor workers (e.g., body temperature, heart rate). Rotate workers to tasks that do not require protective clothing for part of the shift. Encourage removal of protective clothing when on rest breaks, when possible. Provide personal cooling measures (e.g., water-dampened clothing, cooling vests, misting or cooling stations).
Recommended Precautions When Heat Index levels reach High or Very High to Extreme Risk: Emergency Planning and Response (remember, these are in addition to the precautions already listed for all 3 categories): Alert workers to the high or very high to extreme heat index and identify all precautions in place at the work site. Call 911 and cool a worker who is unconscious, confused, or uncoordinated. This may be heat stroke, a medical emergency.
Recommended Precautions When Heat Index levels reach Very High to Extreme Risk: Emergency Planning and Response Have a knowledgeable person on site to not only determine work/rest schedule but also to conduct physiological monitoring.
Heat Index- Quick Reference Table This table provides a quick reference guide for the purpose of awareness, and is good to post in visible locations. May vary by 1 degree Refer to the recommended guidelines for proper details.
Buddy System and Supervisors Set up a buddy system to enable workers to look out for signs and symptoms of heat-related illness in each other. Keep an eye on your coworkers. Supervisors should routinely check on workers and encourage water and rest breaks.
Heat Illness- Treatment Heat Cramps Move to a Cool Environment Rest Drink Water, Salty Drinks, Sports Drink Replenish Salt and Electrolytes Massage Cramps If No Change in 1 Hour Seek Medical Assistance STOP at First Symptoms
Heat Illness- Treatment Heat Exhaustion Call for Emergency Medical Assistance Move to a Cool Environment Drink Fluids if Possible Do not Force Fluids if Confused or Unconscious Replenish Salt and Electrolytes Lie Flat with Feet Slightly Elevated
Heat Illness- Treatment Heat Stroke Medical Assistance Immediately Call 911 IMMEDIATELY! Move to Cool Environment Wrap in Cool, Wet Dressings Sponge Body with Cool Water Ice Packs in Groin, Neck, Arm Pits Blow Cool Air on Person Monitor Temperature Monitor Vital Signs Move to Hospital ASAP
Recognize and Expect Confusion Heat illness can make the worker confused, resistant to help and even combative. Try to calm them, explain to them what is going on and assure them they will be okay.
Other Factors to Consider Good employees want to get-the-job done, sometimes too much so. Slow down in heat, pace yourself. Mechanical assistance using machines or equipment helps to reduce the physical exertion of the worker and aids in keeping the body temperature down.
Easier to Make Mistakes It can be easier to make mistakes or be injured when working in extreme heat due to: Difficulty in concentrating Easier to be frustrated Short tempers Slippery hands Hot surfaces, tools and equipment Sweat getting in eyes
Pre-Job Briefings Discuss the heat stress hazards and precautions during the pre-job briefing. List the steps on your pre-job briefing document.
Post- Incident The occurrence of a heat related illness may indicate a need to re-evaluate exposure times and control measures. Additional monitoring of the workforce and environment may also be necessary. Once the event has passed, hold a job briefing with all supervisors and workers, and discuss what went wrong and what measures are to be followed going forward.
Prevention Review 1. Dress in loose, light weight, and light colored clothing 2. Refrain from alcohol and caffeine consumption during high temperatures 3. Get plenty of rest when not working, and eat a good diet 4. Stay hydrated; drink plenty of water and drinks that contain salt and electrolytes 5. Stay out of heat as much as possible 6. Know and monitor the symptoms of Heat Illness (No One Knows Your Body Like You)
Prevention Review 7. STOP if uncertain at all about symptoms 8. Take plenty of breaks in a cool environment 9. Use cool vests if needed in extreme heat environments 10.Watch out for each other; supervisors watch your workers for signs and following preventative measures 11.Use engineering controls when possible; such as cool rooms, fans, etc. 12.Follow the heat index and work/rest cycle guidelines *Never, Ever Continue to Work when Experiencing Symptoms of Heat Illness. Once You Have Reached Extreme Symptoms It May Be Too Late!
Don t Let This Happen To You
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