Environmental Engineering Reference
In-Depth Information
is. dificult. to. predict.. Heat. stroke. is. a. medical. emergency.. The. primary.
signs.and.symptoms.of.heat.stroke.are.confusion;.irrational.behavior;.loss.
of..consciousness;.convulsions;.a.lack.of.sweating.(usually);.hot,.dry.skin;.
and. an. abnormally. high. body. temperature. (e.g.,. a. rectal. temperature. of.
105.8°F)..If.body.temperature.is.too.high,.it.causes.death..Elevated.meta-
bolic.temperatures.caused.by.a.combination.of.workload.and.environmen-
tal.heat.load,.both.of.which.contribute.to.heat.stroke,.are.highly.variable.
and.dificult.to.predict.
.
. . If. a. worker. shows. signs. of. possible. heat. stroke,. professional. medical.
treatment.should.be.obtained.immediately..The.worker.should.be.placed.in.
a.shady.area.and.the.outer.clothing.should.be.removed..The.worker's.skin.
should.be.wetted.and.air.movement.around.the.worker.should.be.increased.
to. improve. evaporative. cooling. until. professional. methods. of. cooling. are.
initiated.and.the.seriousness.of.the.condition.can.be.assessed..Fluids.should.
be.replaced.as.soon.as.possible..The.medical.outcome.of.an.episode.of.heat.
stroke.depends.on.the.victim's.physical.itness.along.with.the.timing.and.
effectiveness.of.irst.aid.treatment..Regardless.of.the.worker's.protests,.no.
employee.suspected.of.being.ill.from.heat.stroke.should.be.sent.home.or.left.
unattended.unless.a.physician.has.speciically.approved.such.an.order.
.
2.. The.signs.and.symptoms.of.
heat exhaustion
.are.headache,.nausea,.vertigo,.
weakness,.thirst,.and.giddiness..Fortunately,.this.condition.responds.read-
ily.to.prompt.treatment..Heat.exhaustion.should.not.be.dismissed.lightly.for.
several.reasons..One.is.that.the.fainting.associated.with.heat.exhaustion.can.
be.dangerous.because.the.victim.may.be.operating.machinery.or.control-
ling.an.operation.that.should.not.be.left.unattended;.moreover,.the.victim.
may.be.injured.when.he.or.she.faints..Also,.the.signs.and.symptoms.seen.
in.heat.exhaustion.are.similar.to.those.of.heat.stroke..It.is.a.medical.emer-
gency..Workers.suffering.from.heat.exhaustion.should.be.removed.from.the.
hot.environment.and.given.luid.replacement..They.should.also.be.encour-
aged.to.get.adequate.rest.
.
3..
Heat cramps
.are.usually.caused.by.performing.hard.physical.labor.in.a.hot.
environment..These.cramps.have.been.attributed.to.an.electrolyte.imbalance.
caused.by.sweating..It.is.important.to.understand.that.cramps.can.be.caused.
by.both.too.much.and.too.little.salt..Cramps.appear.to.be.caused.by.the.lack.
of.water.replenishment..Because.sweat.is.a.hypotonic.solution.(±0.3.percent.
NaCl),.excess.salt.can.build.up.in.the.body.if.the.water.lost.through.sweating.
is.not.replaced..Thirst.cannot.be.relied.on.as.a.guide.to.the.need.for.water;.
instead,.water.must.be.taken.every.15.to.20.minutes.in.hot.environments..
Under.extreme.conditions,.such.as.working.for.6.to.8 hours.in.heavy.protec-
tive.gear,.a.loss.of.sodium.may.occur..Recent.studies.have.shown.that.drink-
ing.commercially.available.carbohydrate-electrolyte.replacement.liquids.is.
effective.in.minimizing.physiological.disturbances.during.recovery.
.
4.. In.
heat collapse
. (fainting),. the. brain. does. not. receive. enough. oxygen.
because.blood.pools.in.the.extremities..As.a.result,.the.exposed.individual.
may.lose.consciousness..This.reaction.is.similar.to.that.of.heat.exhaustion.
and. does. not. affect. the. body's. heat. balance.. However,. the. onset. of. heat.
