Managing Heat Stress. Enoch Ibarra, RN, OHST, COHN-S

Transcription

1 Managing Heat Stress Enoch Ibarra, RN, OHST, COHN-S

2 Heat Can Kill Monday, July 31, The death toll in California has risen to nearly 150 from unbearable heat. Source: San Francisco Chronicle

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5 Heat Sources

6 Heat Gain by the Body Muscle activity and other body functions Direct radiation from the sun's rays Heat transfer from the air High humidity which hinders the cooling of the body through the evaporation of sweat

7 Radiant Heat Convection Heat Conducted Heat

8 External Heat Sources Radiation Convection Conduction Cooling Evaporation Radiation Convection Conduction

9 Heat Loss by the Body

10 External Heat Sources Isolate heat producing processes Block radiant heat with barriers (shade) Isolate workers from heat Air condition workplace (booth) Capture hot air with exhaust ventilation

11 Internal Source Controls Reduce Workload Improve Ergonomics, Provide Assistance, Increase Relief Time Slow Down Provide Adequate Water Actively Cool Body Acclimatize Gradually Ensure Good Nutrition and Rest

12 Personal Protective Equipment

13 Promote Cooling Wear loose clothing that allows sweat to evaporate easily (cotton) Take internal heat sources into account when using any personal protective clothing that prevents sweat from evaporating Wash clothes regularly and maintain good personal hygiene

14 Heat Illness A serious medical condition resulting from the body's inability to cope with a particular heat load, and includes heat cramps, heat exhaustion, heat syncope and heat stroke.

15 Sun Burn Sunburn is caused by exposure to ultraviolet (UV) radiation from the sun. If you have naturally blonde or red hair, you are more at risk. Some medications may also increase your risk, as can some colognes, perfumes, and soaps.

16 Sun Burn In the worst cases, you can experience severe blistering from sun burn. If a large area is burned, you can get fever, infections, and wind up in shock. First Aid: Cold water compresses are one of the best first-aid measures to relieve pain. Over-the-counter analgesic ointments or sprays may be useful. These can sometimes cause allergic reactions.

17 Prevention Avoid or Limit Sun Exposure Cover Up Use Sun Screen Sunburn is Preventable

18 Transient Heat Fatigue Symptoms: General feeling of tiredness or fatigue. First Aid: Fluid replacement and rest.

19 Heat Rash (prickly heat) Symptoms: Skin becomes reddened and may itch, feel prickly or hurt. First Aid: Practice good personal hygiene; keep the skin clean and the pores unclogged, allow skin to dry, wear loose clothing, see doctor if rash persists.

20 Heat Syncope (fainting) Symptoms: Dizziness, lightheaded and maybe nauseous, then the person may faint. Usually occurs before the circulation system has adapted to heat stress. First Aid: Lay victim in a cool location horizontally with feet elevated. If conscious, give fluids. Treatment the same as shock.

21 Heat Cramps: Symptoms: Cramping of muscles in the arms, legs or abdomen, or both. First Aid: Replenish electrolytes through drinking of fluids such as Gator-Ade, Squincher, PowerAde, etc-ade. Rest in a cool environment.

22 Heat Exhaustion Symptoms: Nausea, dizziness, weakness headache, blurred vision, profuse sweating, cold/wet (clammy) skin, unconsciousness, coma and death. First Aid: Place victim in a cool location, administer fluids if the victim is conscious. If unconscious, seek medical care or transport to a medical emergency room.

23 Heat Stroke Symptoms: Chills, restlessness, irritability, euphoria, red face and skin, disorientation, hot/dry skin (not always), collapse, unconsciousness, convulsions and death. First Aid: Immediate, aggressive cooling of the victim s body using wet cloths, immersion into cold water or alcohol wipes. Transport to emergency medical facility ASAP!

24 Predisposing Factors Overweight Age (the older - the more sensitive to heat) Previous heat illness Heart disease High blood pressure Inactivity Illness Medication

25 Never ignore symptoms

26 Indirect Health Effects Reduced Work Performance: tired, fatigued workers perform with reduced accuracy, efficiency Increased Accidents: tired, fatigued workers are more susceptible to accident and injury Heart / Lung Strain: if you already have heart, lung, kidney or circulatory problems; heat stress is an added strain on your body that may precipitate serious episodes of acute problems

27 "Staying Safe" Regular rest in a cool or shady place. Regular and adequate hydration. Dress for the conditions Acclimatization helps to reduce injury from heat.

28 Individuals dressed in heavy protective clothing in relatively cool conditions can suffer heat injuries. This can even happen at night time.

29 Use the Buddy System! A worker getting heat exhaustion or heat stroke will no longer realize what s happening to him / her It is vital that co-workers be able to recognize what s happening and intervene Without quick attention, the person could die!

30 Acclimatization Acclimatization is the ability of the body to adapt so that you are better able to cope with environmental and physiological heat stress.

31 Acclimatization Heat acclimatization increases sweating (by %) This enhances the cooling capacity of the body, but can lead to dehydration.

32 When are you acclimatized? Acclimatization requires up to 3 weeks to be fully established and is noticeably decreased after 4 days: Heat exposure for 5 of last 7 days

33 Radiant heat The mid-day sun on average adds a 44.6 F radiant heat load. Working along side a plastics molding machine would F, working in a foundry in general around but not with molten iron would add about F, working with molten iron would add about F radiant heat load

34 Heat injury occurs when: Heat production in the body exceeds its ability to lose heat adequately, resulting in a rise in (body core) temperature to levels at which normal body functions are interfered with.

35 Workload Adjustments Issues such as dehydration, medications, medical conditions and pregnancy should also be of concern.

36 Response Plan Guideline Action Alert - information & water Stop work Warning - education & double water Restrict activity 25% & actively monitor for signs of heat stress Restrict activity 50% & actively monitor for signs of heat stress Restrict activity 75% & actively monitor for signs of heat stress

37 Dehydration To prevent dehydration, take advantage of scheduled water breaks!

38 Dehydration fluid loss time* effects & symptoms (* depends on intensity of work and heat / humidity) 0.75 qt 1 hr unnoticed (at 1.5% weight loss you are considered dehydrated) 1.5 qt 2-3 hrs loss of endurance, start to feel thirsty, feel hot, uncomfortable 2.25 qt 3-4 hrs loss of strength, loss of energy, moderate discomfort 3 qt 4-5 hrs cramps, headaches, extreme discomfort qt 5-6 hrs heat exhaustion, nausea, faint 5+ qt 7+ hrs heat stroke, collapse, unconsciousness taken from: OH&S Canada Volume 69, Number 5, page 52, May 2000

39 Recognize Warning Signs Dizziness Head aches Fatigue and A lack of thirst

40 Signs of Dehydration Skin becomes less elastic Urine becomes concentrated and darker Increased perspiration Accelerated fatigue and reduced endurance Heart rate increases Difficulty concentrating Lethargy & Confusion

41 Dark yellow urine is a sure indicator that the individual is dehydrated and that the fluid consumption must be increased. The aim is to produce urine no darker than color 3 of the Urine Color Chart. Desire to urinate less than twice per day or producing urine darker than color 3 in the chart indicate severe dehydration; you must start drinking immediately.

42 Drink Water Acclimatization does not decrease your body s need for water. Drink plenty of water!

43 Prevention Drink 1 quart of water per hour. Avoid drinks that contain caffeine or alcohol. And take rest breaks in a shady area.

44 How Much Water is Enough? More than you want just to satisfy your thirst Sources of water are: Fluids - 1 cup / 8 oz. every 20 min Foods - fruit & veggies are 90% water To maximize the amount you drink (not too cold, not too warm)

45 What to Drink Sports drinks (Gatorade) are usually not needed (but can be used as first aid for heat cramps). Stay away from caffeinated, carbonated, diet drinks and alcohol they are diuretics. Water is best; juices and / or non-caffeine sport drinks are also good (juices contain energy restoring glucose).

46 Eat Healthy You can and should replace essential elements lost during sweating; Eat a balanced diet instead of taking salt tablets or drinking expensive sports drinks.

47 Cooling Fans The purpose of a cooling fan is to increase the rate of sweat evaporation but it also cools by convection if the air is cooler than the skin Fan coolers may interfere with local exhaust ventilation, so be careful where they are placed and how they are pointed

48 Cooling Fans (limitations) If the relative humidity is over 75-80% the fan will no longer increase evaporation of sweat The closer the air temperature is to skin temperature (35-36 C) the less effective the cooling if the air temperature exceeds skin temperature then the fan may even heat up the body (like a convection oven)!

49 Personal Protective Equipment Special cooling vests or ice vests have been developed to wear under chemical resistant suits

50 Shade*

51 Shade* Shade must be provided whenever the outdoor temperature high for the area closest to the location at which employees are to work is forecast, as of 5 p.m. the previous day, to be over 85 degrees F, according to the National Weather Service.

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53 Shade* If the actual temperature exceeds 90 degrees F, shade must actually be present regardless of the previous day's predicted high. Effective date March 17, 2009

54 Shade* The amount of shade is sufficient if there is enough to accommodate, at the same time, 25 percent of the employees on a shift, so that employees can sit comfortably in the shade without touching each other.

55 Shade* The shade must be reachable within a 2 1/2 minute walk. In no case is it permissible for shade to be located more than 1/4 mile or a five minute walk away, whichever is shorter.

56 Shade* Areas shaded by artificial or mechanical (as opposed to natural) means, such as by a popup canopy as opposed to a tree, must allow for employees to avoid contact with bare soil.

57 Shade* This can be done by providing chairs, benches, sheets, towels, or any other items that let employees sit and rest without contacting dirt. Where the shaded area is a lawn, no such item need be provided, regardless of the means by which the area is shaded.

58 questions? heatillnessqa.html

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