Managing Heat StressAnd getting the job done without injury.

Background

Heat is the leading weather-related killer in the United States, resulting in hundreds of deaths each year.

Kills an average of 175 each year nationwide - more than tornadoes, hurricanes, lightning, or floods.

2,590 heat related deaths from 1986 to 2003

Killer Heat

In the disastrous heat wave of 1980, more than 1,250 people died.

In the heat wave of 1995 more than 700 deaths in the Chicago area were attributed to heat, making this the deadliest weather event in Chicago history.

What heat stress situations have you seen?

Heat Illness Video

Heat Management is Good for Business

Source: NASA CR-1205-1, "A Compendium of Human Responses to the Aerospace Environment".*

When in-plant temperatures rise over 85°, output drops by 18% and accuracy suffers from a 40% increase in errors.

Productivity losses from high temperatures may be documented by your own production records.

HEAT DISORDERS

Heat Cramps

Heat Exhaustion

Heat Stroke

Dangers of Heat Sress Video

HEAT CRAMPS

Symptoms: Painful muscle cramps and spasms, usually in muscles of

legs and abdomen. Heavy sweating.

First Aid: Apply firm pressure on cramping muscles or gently

massage to relieve spasm.

Give sips of water; if nausea occurs, discontinue water intake. Consult with a clinician or physician if individual has fluid restrictions (e.g., dialysis patients).

HEAT EXHAUSTION

Symptoms: Heavy sweating, weakness, cool skin, pale, and clammy.

Weak pulse. Normal temperature possible. Possible muscle cramps, dizziness, fainting, nausea, and vomiting.

First Aid: Move individual out of sun, lay him or her down, and

loosen clothing. Apply cool,wet cloths. Fan or move individual to airconditioned room.

Give sips of water; if nausea occurs, discontinue water intake. If vomiting continues, seek immediate medical attention. Consult with a clinician or physician if individual has fluid restrictions (e.g., dialysis patients).

HEAT STROKE (or sunstroke)Symptoms: Altered mental state. Possible throbbing headache,

confusion, nausea, and dizziness. High body temperature (106°F or higher). Rapid and strong pulse. Possible unconsciousness. Skin may be hot and dry, or patient may be sweating. Sweating likely especially if patient was previously involved in vigorous activity.

First Aid: Heat stroke is a severe medical emergency.

Summon emergency medical assistance or get the victim to a hospital immediately. Delay can be fatal. Call x5911 first!

Move individual to a cooler, preferably air-conditioned, environment. Reduce body temperature with a water mister and fan or sponging. Use air conditioners. Use fans if heat index temperatures are below the high 90s. Remove clothing. If temperature rises again, repeat process. Do not give fluids.

RE-CAP:

What are the symptoms of heat stroke?

Altered mental state; possible unconsciousness

Possible throbbing headache, confusion, nausea, dizziness, shallow breathing

High body temperature (106°F or higher); rapid pulse

Protecting Workers

General Precautions

Water Loss

Normally, with light activity, your body looses 2 to 3 quarts of water daily. Your thirst mechanism is not sensitive enough to be an accurate indicator of your body’s needs.

In a hot weather environment, you loose 6 to 8 quarts of sweat which is critical to cool your body.

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.

Urine Color Level Hydration Chart

Protect Yourself and Your Team

Drink plenty of non-alcoholic and decaffeinated fluids. Your body needs water to keep cool. Drink even if you don't feel thirsty.

Dress for summer. Wear lightweight, light-colored clothing to reflect sunlight.

Plan ahead, slow down, and use rest schedules. Reduce, eliminate or reschedule strenuous activities until the coolest time of the day.

Don't get too much sun. Sunburn reduces your body's ability to dissipate heat.

Do not take salt tablets unless specified by a physician.

Provide shade, fans, and other engineering controls in the work area.

Stay in communication range: use the buddy system!

Take time to acclimate new and returning workers.

Protect Yourself and Your Team

Acclimation People are, to a large extent, capable of adjusting to the

heat. Much of this adjustment to heat, under normal circumstances, takes about a week.

On the first day of work in a hot environment, the body temperature, pulse rate, and general discomfort will be higher. With each succeeding daily exposure, all of these responses will gradually decrease, while the sweat rate will increase.

The body will undergo a series of changes that will make continued exposure to heat more endurable. However, it may take up to several weeks for the body to fully acclimate.

Acclimatization can occur naturally, however, implementing acclimatization activities is essential for new workers, workers who have been out sick or on vacation, and all workers during a heat wave.

Develop a heat acclimatization plan. For example, allow workers to get used to hot environments by

gradually increasing exposure over at least a 5-day work period. Begin with 50% of the normal workload and time spent in the hot environment and then gradually build up to 100% by the fifth day. New workers and those returning from an absence of two weeks or more should have a 5-day minimum adjustment period. While a significant amount of acclimatization occurs rapidly in that first week, full acclimatization may take a little longer. Some workers require up to two or three weeks to fully acclimate.

Factors that increase acclimation time include diabetes, kidney and heart problems, pregnancy, and being overweight. Children produce heat at a faster rate than adults and are at greater risk of heat disorders.

Acclimation

Forecasts and Advisories

NOAA's Extreme Heat Watch, Warning, and Advisory Products Excessive Heat Warning/Advisories are issued an

excessive heat event is occurring, is imminent, or has a very high probability of occurring. The warning is used for conditions posing a threat to life. An advisory is for less serious conditions.

Excessive Heat Watches are issued when the risk of a heat wave has increased but its occurrence and timing is still uncertain. A watch provides enough lead time so that those who need to prepare can do so, such as cities officials who have excessive heat event mitigation plans.

Excessive Heat Outlooks provides information to those who need considerable lead time to prepare for the event, such as public utility staff, emergency managers and public health officials.

Heat Index / WBGT NOAA's heat alert procedures are based mainly on Heat

Index values. The Heat Index is given in degrees Fahrenheit and is an estimate of how hot it feels when a person’s ability to sweat is factored in with the air temperature measured in the shade.

The Heat Index assumes workers are in the shade and does not factor in solar radiation which can add as much as 15 deg F. This also assumes the person is physically fit and is wearing appropriate clothing.

To address these shortcomings, the Marines developed the Wet Bulb Globe Temperature (WBGT) method. 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 other method. WSMR WBGT Hotline: 575-524-3333

Heat Index

Heat Index Notes

80–90 °F Caution: fatigue is possible with prolonged exposure and activity. Continuing activity could result in heat cramps.

90–105 °F Extreme caution: heat cramps and heat exhaustion are possible. Continuing activity could result in heat stroke.

105–130 °F

Danger: heat cramps and heat exhaustion are likely; heat stroke is probable with continued activity.

over 130 °F Extreme danger: heat stroke is imminent.

Heat Index Forecasts

3-Day Forecasts: http://www.hpc.ncep.noaa.gov/heat_index.shtml

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.

(numbers are Wet Bulb Globe Temperature Index – not the dry bulb temperature)

Military Heat Stress Flag Colors

Yellow- 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.

Communicating Heat Hazards

Daily Email Advisories from WSTF-Today Referencing the Heat Index Forecast maximum for the day, identify

the heat index at El Paso and select the entry closest to 90% probability.

Communicate the daily maximum heat index and issue an alert, similar to the following:

Heat Index for Today: 92F, Risk Level Moderate Remind workers to drink water often (about 4 cups/hour)

Review heat-related illness topics with workers: how to recognize heat-related illness, how to prevent it, and what to do if someone gets sick

Develop work/rest schedules and schedule frequent breaks in cool, shaded area

Acclimatize workers and monitor workers closely

Set up buddy system/instruct supervisors to watch workers for signs of heat-related illness

If workers must wear heavy protective clothing, perform strenuous activity or work in the direct sun, additional precautions are recommended to protect workers from heat-related illness. Schedule activities at a time when the heat index is lower

Protective MeasuresSetting work/rest schedules

Rest Areas Advise workers of the work/rest schedule and make

sure supervisors enforce rest breaks.

Provide air conditioned or cool, shaded areas close to the work area for breaks and recovery periods.

Set up temporary shade when working in open fields or areas without easy access to shade or air conditioning.

Encourage workers to remove protective equipment that is not needed while they are on rest breaks (e.g., if the rest area is free of hazards, remove hard hat, gloves, high visibility vest, respirator, and protective suit).

Drinking Water

Water should have a palatable (pleasant and odor-free) taste and water temperature should be 50°F to 60°F, if possible.

Sanitation standard 29 CFR 1910.141 requires that employers provide "potable water" at work sites, which is water that meets the drinking water standards of the state or local authority having jurisdiction, or water that meets the quality standards prescribed by the U.S. EPA’s drinking water regulations (40 CFR Part 141).

Adjust Work Activities

Work on a buddy system. Instruct supervisors to watch workers for signs of heat-related illness. Maintain effective communication with your crew at all times.

Set up shade canopies over work areas in direct sunshine or move jobs that can be moved to naturally shaded areas.

Permit only those workers acclimatized to heat to perform the more strenuous tasks. Decrease the physical demands and pace of jobs. Rotate workers to job tasks that are less strenuous. Add extra personnel to physically demanding tasks and those requiring the use of heavy or non-breathable clothing.

Provide workers with personal cooling measures.

Encourage workers to wear sunscreen and use other protections from direct sunlight.

Setting Work / Rest Schedules to Mitigate Heat IllnessACGIH/OSHA “A Guide to Heat Stress in Agriculture”

• When WBGT is unavailable, adjust the temperature reading in °F as follows before going to the temperature column in the table:

• 45/15 minutes = 45 minutes work and 15 minutes rest during each hour.

• “Caution” Indicates very high levels of heat stress. Consider rescheduling activities for a time when the risk of heat illness is lower.

Setting Work / Rest Schedules to Mitigate Heat IllnessExample Scenario

• The weather is 95 °F in the shade, sunny, and the relative humidity is 38%. Heavy work is to be done, such as moving heavy materials with a wheelbarrow. Determine the suggested work/rest schedule.

• Start with 95° and add 13° because it’s sunny [95°+13° = 108°]. Because of humidity, we also add 3° [108° + 3° = 111°].

• It is unsafe to work in these conditions. Provide shade in the work area for 35/25.

Setting Work / Rest Schedules to Mitigate Heat IllnessAssumptions

The ACGIH Method for Assessing Heat Stress applies to: heat-acclimatized adults under the age of 40

physically fit and well-rested

fully hydrated with adequate water intake

natural ventilation with perceptible air movement

air temperature readings in Fahrenheit, taken in the shade

30% relative humidity

Setting Work / Rest Schedules for TES SuitsOverview

This table is based on values for heat-acclimatized adult workers

under the age of 40 who are physically fit

well-rested, and fully hydrated with adequate water intake

wearing Tyvek coveralls, gloves, boots, and a respirator

Cooling vests may enable workers to work for longer periods. Adjustments must be made when additional protective gear is worn.

Humidity does not factor into this table as sweating no longer removes body heat in this scenario.

Examples of Light WorkExample Motions

Sitting with light manual work with hands and arms

Driving

Standing with some light arm work and occasional walking

Casual walking (2 miles per hour)

Lifting 10 pounds fewer than eight times per minute, or 25 pounds less than four times per minute

Example Tasks

Using small bench tools or small power tools

Inspecting and sorting produce

Sorting light materials

Assembling small parts

Nailing

Examples of Moderate WorkExample Motions

Sustained moderate hand and arm work

Moderate arm and leg work

Moderate arm and trunk work

Moderate pushing and pulling

Walking at a moderate speed

Lifting 10 pounds 10 times per minute, or 25 pounds six times per minute

Example Tasks

Picking fruits and vegetables (bending, squatting)

Painting with a brush

Pushing or pulling lightweight carts or wheelbarrows

Off road operation of trucks, tractors or construction equipment

Operating an air hammer

Weeding or hoeing

Examples of Heavy WorkExample Motions

Intense arm and trunk work

Carrying, shoveling, manual sawing

Pushing or pulling heavy loads

Walking at a fast pace (4 miles per hour)

Lifting 10 pounds 14 times per minute, or 25 pounds 10 times per minute

Example Tasks

Transferring heavy materials, shoveling

Sledgehammer work

Hand mowing, digging

Concrete block laying

Pushing or pulling loaded hand carts or wheelbarrows

Additional Resources OSHA’s Heat Safety Tool (Free)

(Android / iPhone)

The App allows workers and supervisors to calculate the heat index for their worksite and, based on the heat index, displays a risk level to outdoor workers.

With a simple "click" you can get reminders about the protective measures that should be taken at that risk level.

Using the Heat Index: A Guide for Employers

Excessive Heat Events Guidebook

OSHA Resources

Printable Heat Index Chart

http://www.wrh.noaa.gov/psr/general/safety/heat/heatindex.png

Never Leave Children, Disabled Adults or Pets in Parked Vehicles Make sure your child's safety seat and safety

belt buckles aren't too hot before securing your child in a safety restraint system, especially when your car has been parked in the heat.

Never leave your child unattended in a vehicle, even with the windows down.

Teach children not to play in, on, or around cars.

Always lock car doors and trunks--even at home--and keep keys out of children's reach.

Always make sure all children have left the car when you reach your destination. Don't leave sleeping infants in the car ever