Environmental Engineering Reference
In-Depth Information
Susceptibility.to.cold.injury.varies.from.person.to.person..In.general,.people.in.
good.physical.health.are.less.susceptible.to.cold.injury..Conditions.that.worsen.the.
risk.of.cold.injury.include.the.following:
•.
Sex
•.
Old.age
•.
Diseases.of.the.blood.circulation.system
•.
Previous.cold.injury
•.
Raynaud's.disease
•.
Fatigue
•.
Consumption.of.alcohol.or.nicotine
•.
Use.of.certain.drugs.or.medication
•.
Injuries.resulting.in.blood.loss.or.altered.blood.low
Although.people.easily.adapt.to.hot.environments,.they.do.not.acclimatize.well.to.
cold..However,.frequently.exposed.body.parts.can.develop.some.degree.of.tolerance.
to.cold..Blood.low.in.the.hands,.for.example,.is.maintained.in.conditions.that.would.
cause.extreme.discomfort.and.loss.of.dexterity.in.unacclimatized.persons..This.is.
noticeable. among. ishermen. who. are. able. to. work. with. bare. hands. in. extremely.
cold weather.
Workplace. conditions. that. inluence. cold. stress. are. the. severity. of. cold. stress,.
which.depends.on.the.air.temperature,.wind.speed,.and.intensity.of.physical.activity..
Air.temperature.is.measured.by.an.ordinary.thermometer.in.degrees.Fahrenheit.or.
Celsius..Different.types.of.commercially.available.anemometers.are.used.to.measure.
wind. speed. or. air. movement.. These. are. calibrated. in. miles. per. hour. (mph).. The.
following.is.a.suggested.guide.for.estimating.wind.speed,.if.accurate.information.is.
not.available:
•.
Light.lag.moves.(5.mph)
•.
Light.lag.fully.extended.(10.mph)
•.
Raises.newspaper.sheet.(15.mph)
•.
Causes.blowing.and.drifting.snow.(20.mph)
The. production. of. body. heat. by. physical. activity. (metabolic. rate). is. dificult. to.
measure.. At. any. temperature,. one. feels. colder. as. the. wind. speed. increases.. The.
combined.effect.of.cold.air.and.wind.speed.is.expressed.as.wind-chill.temperature.
in.degrees.Fahrenheit..This.is.essentially.the.air.temperature.that.would.produce.the.
same. cooling. effect.on. exposed. human. lesh. as.the.given. combination. of. air. tem-
perature.and.wind.speed.(see.Table 23.1).
In.the.United.States.there.are.no.OSHA.exposure.limits.for.cold.working.environ-
ments..It.is.often.recommended.that.work.warm-up.schedules.be.developed..In.most.
normal. cold. conditions,. a. warm-up. break. every. 2. hours. is. recommended,. but,. as.
temperatures.and.wind.increase,.more.warm-up.breaks.are.needed.
For.continuous.work.in.temperatures.below.the.freezing.point,.heated..warming.
shelters. such. as. tents,. cabins,. and. rest. rooms. should. be. made. available.. The. pace.
of. work. should. not. be. so. heavy. as. to. cause. excessive. sweating.. If. such. work. is.
