Environmental Engineering Reference
In-Depth Information
tABle 23.1
Windchill Factor: cooling Power of Wind on exposed Flesh expressed as an
equivalent temperature (under calm conditions)
Actual thermometer reading (°F)
50
40
30
20
10
0
−10
−20
−30
−40
−50
−60
estimated Wind
speed (mph)
equivalent temperature reading (ºF)
Calm
50
40
30
20
10
0
−10
−20
−30
−40
−50
−60
5
48
37
27
16
6
−5
−15
−26
−36
−47
−57
−68
10
40
28
16
4
−9
−24
−33
−46
−58
−70
−83
−95
15
36
22
9
−5
−18
−32
−45
−58
−72
−85
−99
−112
20
32
18
4
−10
−25
−39
−53
−67
−82
−96
−110
−124
25
30
16
0
−15
−29
−44
−59
−74
−88
−104
−118
−133
30
28
13
−2
−18
−33
−48
−63
−79
−94
−109
−125
−140
35
27
11
−4
−20
−35
−51
−67
−82
−98
−113
−129
−145
40
26
10
−6
−21
−37
−53
−69
−85
−100
−116
−132
−148
Wind.speeds.
greater.than.40.
mph.have.little.
added.effect.
Little.danger.(for.properly.
clothed.person)..
Maximum danger.of.false.
sense.of.security.
Increasing.danger..
Danger.from.
freezing.of.
exposed lesh.
Great.danger.
Trenchfoot.and.immersion.foot.may.occur.at.any.point.on.this.chart.
Source:
. NAVMED.Bulletin.5052-29.
necessary,.proper.rest.periods.in.a.warm.area.should.be.allowed.for.changing.into.
dry.clothes..New.employees.should.be.given.enough.time.to.become.accustomed.to.
cold.and.protective.clothing.before.assuming.a.full.workload.
The.risk.of.cold.injury.can.be.minimized.by.proper.equipment.design,.protective.
clothing,. and. safe. work. practices.. For. work. performed. below. the. freezing. point,.
metal. handles. and. bars. should. be. covered. by. thermal. insulating. material.. Also,.
machines.and.tools.should.be.designed.so.that.they.can.be.operated.without.having.
to.remove.gloves.
Protective. clothing. is. needed. for. work. at. or. below. 40°F.. Clothing. should. be.
selected.to.suit.the.degree.of.cold,.level.of.activity,.and.job.design..Clothing.should.be.
worn.in.multiple.layers,.which.provides.better.protection.than.a.single.thick..garment..
The.layer.of.air.between.clothing.provides.better.insulation.than.the..clothing.itself..
In.extremely.cold.conditions,.where.face.protection.is.used,.eye.protection.must.be.
separated.from.respiratory.channels.(nose.and.mouth).to.prevent.exhaled.moisture.
from.fogging.and.frosting.eye.shields.
For.work.in.wet.conditions,.the.outer.layer.of.clothing.should.be.waterproof..If.
the. work. area. cannot. be. shielded. against. wind,. an. easily. removable. windbreaker.
garment.should.be.used..Under.extremely.cold.conditions,.heated.protective.clothing.
should.be.made.available..Clothing.should.be.kept.clean,.as.dirt.ills.air.cells.in.ibers.
of.clothing.and.destroys.its.insulating.ability..Clothing.must.be.dry..Moisture.should.
