Heat Stress HSE Presentation regarding heat stress

safety

1. Heat Stress

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Doing too much on a hot day, spending too much time in
the sun or staying too long in an overheated place can cause
heat-related illnesses.
Heat attack
Hot temperatures and high humidity stress the body’s ability
to cool itself, resulting in heat sickness. It is important to
recognise the symptoms at an early stage in order to guard
yourself from serious consequences.

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•Dehydration-is the loss of fluids from the body. The human body
needs water for vital organs such as the brain, kidney and heart to
function properly.
Know the difference
It is important to note the difference between various heat illnesses.
•Heat rash-is a skin irritation caused by excessive perspiration.
•Heat cramps-are severe and painful cramping of the muscles due
to imbalances in body fluids and excessive perspiration.
•Heat syncope or fainting-dizziness that can result in fainting when
standing continuously under the hot sun for a long time.

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Heat exhaustion-results when losing body fluids through
perspiration during heat exposure.
The body cools off by evaporation of sweat but gets exhausted
when the sweat exceeds the volume of water or fluid drunk.
Sun burn-is a painful skin condition which occurs as a
result of overexposure to the ultra-violent rays of the
sun. This can damage the outer layers and inner tissues
of the skin. It can also lead to skin cancer.
Heatstroke or sunstroke-is a deadly heat illnesses. It
occurs when the body’s control temperature system
stops functioning. The body temperature rises rapidly,
the sweating mechanism fails and the body is unable to
cool down. This can lead to death, brain damage or
permanent disability if emergency treatment is not
provided.

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How to recognise, treat and avoid heat illnesses?
Type Symptoms Treatment
Dehydration
1. Flushed face.
2. Extreme thirst, more than
normal or unable to drink.
3. Dry, warm skin.
4. Dizziness made worse when you
are standing.
5. Weakness.
6. Cramping in the arms and legs.
7. Headaches.
8. Dry mouth, dry tongue.
9. Low blood pressure.
10. Rapid and deep breathing -
faster than normal.
11. Fainting.
For mild to
moderate
dehydration
drink more
water and try
to avoid the
heat until
refreshed.

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Type Symptoms Treatment
Heat Rash
1. Redness accompanied with
swelling and inflammation
of skin.
2. Small blisters.
Both symptoms commonly
occur on the back of the neck.
The best treatment is
to provide a cooler and
less humid environment.
Clean the affected area
and apply mild lotions
to it.
Heat Cramps
1. Muscle pain in the
abdomen, arms or legs may
occur in association with
strenuous activity.
2. Rapid heartbeat.
3. Hot sweaty skin.
Stop all activities and
do not return to
strenuous activities until
the cramps subside as
further exertion may
lead to exhaustion or
heat stroke This usually
improves with drinking
water and resting in a
cool environment.

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Type Symptoms Treatment
Heat Syncope
Or Fainting
1. Faintness.
2. Dizziness.
3. Headaches.
4. Increased pulse rate.
5. Restlessness.
6. Nausea.
7. Vomiting.
8. Possibly even a brief
loss of consciousness.
Lie or sit down, preferably in
the shade or in a cool
environment.
Try to take frequent breaks if
working under high
temperatures and drink a lot
of water.
Heat exhaustion
1. Headaches.
2. Paleness.
3. Heavy sweating.
4. Intense thirst.
5. Dizziness.
6. Fatigue.
7. Nausea.
8. Impaired judgment.
9. Loss of appetite.
Shift to a cooler location and
drink a lot of water or a light
juice.
Use cold towels over your
head and neck.

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Type Symptoms Treatment
Sunburn
1. Skin becomes red &
painful.
2. Burning sensation and
swelling.
3. Blisters.
•Apply cold towels on the
areas affected or take a cold
shower.
•Apply moisture lotions and
not ointments.
•Do not break blisters and try
to avoid repeated sun
exposure.
•Use sunscreen to avoid a
sunburn.
Seek medical attention for
severe cases
Heatstroke /
Sunstroke
1. High body
temperature.
2. Red hot and dry skin.
3. Throbbing headaches.
4. Nausea.
5. Unconsciousness.
6. Rapid and shallow
breathing.
7. Fatigue.
•Get to a shady cool area.
•Sponge or shower with cold
water.
•Get a cold towel and rapid it
around the body.
•Call the hospital for medical
treatment.

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Temperature & Humidity Combined
Below is a diagram indicating the temperature and humidity level that you
need to be careful of.
70 %
60 %
50 %
40 %
30 %
100°F/ 37.8°C
95°F/ 35°C
90°F/ 32.2°C
85°F/ 29.4°C
80°F/ 26.7°C
Dangerous
Caution
Less
Hazardous
Relative
Humidity
Temperature

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Engineering Controls
1. General Ventilation-
General ventilation can dilute hot air with cooler air (generally
brought in from the outside). This technique clearly works better in
cooler climates than in hot ones. Large areas or entire buildings
identified as high heat areas may require a permanently installed
ventilation system to reduce temperature levels. In smaller areas,
portable or local exhaust systems may be more effective or practical.
2. Local Ventilation-
Reduce heat stress by increasing the airflow and velocity with fans
and other movers in the work area (as long as the air temperature is
less than the person's skin temperature). If the air temperature is
higher than about 100to 104F, skin warming may offset any
advantage gained by evaporative cooling. Because this method does
not cool the air, the increased air flow must contact the worker
directly to be effective. This control will have little, if any, positive
effect on workers wearing vapor-barrier clothing.

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3. Air Treatment / Air Cooling-
This control measure differs from ventilation because it cools the air by
removing heat (and sometimes humidity). Air conditioning and air
treatment devices may be expensive to install and operate. Nonetheless,
mechanical refrigeration can be effective in specific areas such as "cool
rooms" (used as recovery areas near hot jobs). Portable blowers with a
built-in air chiller are effective for cooling asbestos abatement (and similar)
enclosures. The main advantages of blowers are portability and minimal
set-up time.
4. Radiant Heat Reduction-
Reflective heat shields and insulation will reduce radiant heat. With
sources of radiation such as heating pipes, it is possible to use both
insulation and surface modifications to achieve a substantial reduction in
radiant heat. If shields are used, it is important to minimize their influence
on the cooling effects of air flow.
5. Shade-
Shade will reduce radiant solar heat and is a widely recognized control
measure. Shading the work area, rest areas, or equipment or enclosures can
significantly decrease the heat load.

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Administrative and Work Practice Control
1. Scheduling-
Ifpossible,performpotentiallyhotjobswhenheatstressconditionsareat
theirminimum.Allowlatentheatinequipmenttodissipatebeforework
begins.Scheduleworkforthecoolerpartoftheday,andscheduleroutine
maintenanceandrepairworkinhotareasforthecoolerseasonsoftheyear.
2. Fluid Replacement-
Placeamplesuppliesofliquidsclosetotheworkarea.Preferreddrinksare
low-sodium,non-carbonated,non-alcoholic,andnon-caffeinated.They
shouldbeprovidedat50-60F.Becausethenormalthirstmechanismdoes
notensuresufficientfluidintake,encourageworkerstodrinksmallamounts
onafrequentbasis,e.g.,one4-ounceto6-ouncecupevery20minutes.The
tasteofcommerciallyavailablebalancedelectrolytereplacementdrinksmay
alsoencouragefluidintake.(Theseproductsareperfectlyacceptablewhen
diluted50%inwater.)Althoughsomecommercialelectrolytereplacement
drinkscontainsalt,thisisnotnecessaryforacclimatedindividualswho
generallyaddenoughsaltintheirdiets.

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3. Acclimation-
Mostpeoplegetusedtoheatexposureuptoapoint.Thisiscalled
acclimationanditresultsinlesscardiovasculardemandforagiven
activity.Theworkerwillsweatmoreefficiently(increasingevaporative
cooling)andmayloselesssalt,thuswillmoreeasilymaintainnormal
bodytemperature.Acclimationdecreasestheriskofheat-related
illnessesandassociatedunsafeacts.
Deliberateacclimationinvolvesexposingemployeestoworkinahot
environmentforprogressivelylongerperiods.Forworkerswithrecent
experience(withintwoweeks)injobswhereheatlevelsmayproduce
heatstress,NEBOSHrecommendsthefollowingregimen:50%of
normalexposureondayone,60%ondaytwo,80%ondaythree,and
100%percentondayfour.Fornewworkerswhowillbesimilarly
exposed,theregimenshouldbe20%ondayone,witha20%increasein
exposureeachadditionalday.
4. Work/Rest Cycles-
Prescribedperiodsofworkandrestarebasedonspecificheatindicesand
workloadestimates(e.g.,ACGIH-TLVs).Theseprescribedlevelsare
basedontheassumptionthattheworkisrepetitive,controlled,and
continuousoveraneight-hourshift,andthattherestareaisinan
environmentsimilartothatinwhichtheexposureoccurs.

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5. Recovery Times-
Recoverymayberequiredforanyheatstressexposure.Recoveryis
completewhentheperson'sphysiologicalstatehasreturnedtoitspre-
exposurecondition.Thismeansthatexcess(stored)bodyheathasbeen
dissipated,lostfluidhasbeenreplaced,andelectrolytesareinbalance.
Topermitdissipationofstoredbodyheat,therecommendedrecovery
areashouldbesubjectivelycool.
6. Buddy System-
Workinginpairsorsmallteamsallowsappropriatelytrainedworkersto
observeeachotherforsignsofheat-relateddisorders.Employeesmay
alsoshareworkactivitiestoreducemetabolicheatproduction.
7. Personal Monitoring-
Anindividual'sphysiologicalresponsetoheatstresscanbemonitored
withavarietyofinstrumentsavailableonthemarket.Theinstruments
measureskinorearcanaltemperatureasasurrogateforcorebody
temperature.Someinstrumentsalsomeasureheartandrespirationrates.
Unfortunately,thereislimitedconsensusinthescientificcommunityon
howtointerprettheresults.

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Mostindividualscanbetrainedtomonitortheirownheartrate.Healthy,
acclimatedworkersshouldavoidprolongedwork/environment
combinationsthatcausetheirheartratetoexceedtherecommended
maximumheartrate,MHRwhentakenduringthefirstminuteofrest.The
heartrateshoulddropto110-120beatsperminutefollowingthefirst
minuteofrest.
8. Check Times-
Aprescribedchecktime(CT)schedulecanaugmentself-determination.
Checktimesareintervalsatwhichaheatstress-trainedsupervisoror
observer(includingaco-workeror"buddy")mustseekexplicit
confirmationfromindividualheatstress-trainedworkersthateachcan
continuework.Thatis,theobserverdeterminesifthereareobvious
symptomsofheatdisorders,orifthereisanysenseofdiminishedcapacity.
Ifso,theexposureisterminatedandrestisrequired.UsingCTsrequires
eachworker,atregularintervals,toexplicitlyassesshis/herphysiological
stateandabilitytocontinuework,ratherthanwaitingforsymptomsto
appear.

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9. Self-Determination-
Appropriatelytrainedworkerscanhelpmonitortheirownheat
condition.Trainingshouldemphasizethatheatstresscanaffectan
individual'sabilitytoreasonclearly.Thismaycausethemtofailto
recognizesignsandsymptomsofheatstress.Forthisreason,self-
determinationmustbeaugmentedbytheheatawarenessprogram,
workertrainingprogram,andchecktimeandbuddysystemcontrols
describedintheseguidelines.
10. Other Administrative Controls-
Reducethephysicaldemandsofwork(suchasexcessiveliftingor
digging)byusingpoweredequipment,increasethenumberofworkers
assignedtoatask,usereliefworkers,andlimitworkeroccupancyin
confinedareas.

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Heat Awareness Condition
1.A "Heat Awareness Condition" is declared when the potential for heat
stress is significant.
2.The "Condition" is based on the daily weather forecast of the National
Weather Service (NWS) or other competent forecast. (Use the table
below to compute NWS values.) If extremely hot weather is predicted for
the next day or days, a "Heat Awareness Condition" is declared to ensure
that all aspects of this procedure are in place, and that personnel
awareness is heightened. Extremely hot weather is defined here as any of
the following:
Ambienttemperatureinexcessof95F(=35C)
NWSapparenttemperature(AT),orheatindex(HI)inexcessof90F(=32C)
A"HeatAwarenessCondition"mayexistatmanyprojectsitesthroughoutthe
summer.Duringa"HeatAwarenessCondition",thehazardsandcontrolsof
heatarecontinuouslyemphasizedwitheachemployeeandsupervisorduring
TSTI.Workersshouldbeinstructedtointerruptheatexposurebeforetheyfeel
excessivediscomfortorsymptomsofanyheat-relateddisorder.
The"HeatAwarenessCondition"isbasedonpubliclyavailablevaluesthat
makestheprogramunderstandabletomostemployees.Italsomakesthe
programmorepracticalatprojectswithlimitedaccesstoWBGTmonitoring
equipment.Someprojectsadvertisea"HeatAwarenessCondition"byposting
thepredictedheatindexatthefrontgateonasignintheshapeofa
thermometer.

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Hydrations
Thebestwaytoavoidheatstrokesandotherheatdisordersistokeepyourbodywell
hydrated.Drinkalotofwaterifyouareexercisingorworkinginhotconditions.
Doctorsusuallyrecommendconsumingeightormoreglassesofwaterperday.
Ventilation
Remainincoolareaswhereyourbodycancoolitself.Ifworkinginhotconditions,try
totakeabreaktoregainenergyandtoavoidoverexposuretothesun’srays.
Clothing
Whatyouwearplaysabigfactorinhowyourbodywillhandletheheat.Lightclothing
andloosefittingclothingwillhelpyourbodyinbreathingandcoolingitselfnaturally.It
isfinetowearahatorcaptoshieldyourselffromthesunbutonceyoufeelwarm,
removeit.Thisusuallytrapstheheatinsideyourbody.
Limit yourself
Itisalsoimportanttowatchtheamountofactivitiesyouareparticipatinginduringhot
days.Don’toverdoit.Heatstrokeandotherdisorderscantakeaffectinlessthananhour.
Ifyoufeelyourselfgetwarmandsuffocatedwiththeheat,it’sbesttotaketimeoutand
restinashadyarea.
Desert conditions
Indesertenvironmentsonemaynotbeawarethattheyareperspiringduetorapid
evaporation.
General Precautions

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Warning!
Youneedtolearntodrink,evenwhenyouarenotthirsty.
Bythetimeyoufeelthirstyyouarealready10%dehydrated
Urine Colour gives indication of hydration state ie,
(if urine is dark drink more)

20. DW-HSE-TM03520
The color of Urine tells you how dehydrated you are!
Extremely Dehydrated
Drink Water Immediately
Mildly Dehydrated
Drink More Water
Not Dehydrated
HYDRA CHECK -
NOTE: This is a general guide only and in no way replaces medical advice. Not applicable for person taking
medicine and supplemental vitamins.

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Prevention
Start drinking water (before you start
work),
Drink water (As much as you need),
Check your Urine color (note the urine
color),
Ensure adequate ventilation,
Rotate work (from hot to cool areas),
Report to your Supervisor or the Nurse
at first sign of any problem,
Keep an eye on your work mates
Remember!

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Prevention is better than cure !