HEAT CASUALTY--An individual unable to perform
HOT SPOT--A localized area of a ship where
his or her duties as a result of heat exhaustion or heat
chemical or biological contamination is
stroke.
considerably above the average of the surrounding
area.
HEAT EXHAUSTION--A physical condition caused
by exposure to high temperature combined with
HOT SURFACE--NSTM, chapter 505, defines a hot
surface as 650F (343C) for lubricating oil and
physical exertion, and marked by faintness, nausea,
and profuse sweating; can be considerably reduced
hydraulic oil systems and 400F (205C) for all other
by proper physical conditioning and increased fluid
flammable liquids.
intake.
HOT WORK--Any operation that involves flame,
HEAT STRESS--Heat stress is a pathological
spark, or temperatures in excess of 2050C
condition in which the body's cooling mechanisms
(4000F).
are unable to dissipate the heat load generated.
HYCHECK VALVE--Diaphragm type, fail open,
HEAT STRESS PROGRAM--The Heat Stress
seawater pressure-operated control valve, which
Program establishes Navy policy and procedures
allows the flow of seawater from the firemain
for the control of personnel exposure to heat stress.
system to be mixed with AFFF concentrate.
HEAT STROKE--A state of collapse or prostration,
HYDROCARBON--A compound containing only
usually accompanied by high fever, brought on by
carbon and hydrogen. Hydrocarbons are the
exposure to heat; has a 50 percent mortality rate but
principal constituents.
accounts for only a small percentage of heat
casualties.
fires. It is also produced by the rotting of foods,
HEPA FILTER--A high efficiency particulate air
cloth, leather, sewage, and other organic materials.
filter. HEPA filters remove solid particles and liquid
droplets from an air supply.
H Y D R O G E N - I O N C O N C E N T R AT I O N --
Abbreviated pH, term used to express the acidity or
HIGH ALTITUDE BURST--A nuclear detonation
alkalinity.
that takes place at an altitude where the atmosphere
is so thin that the interaction of the explosion with
HYDROLYSIS--The decomposition of a chemical
the atmosphere is drastically different from that of
compound by reaction with water, useful in
bursts at lower altitudes; nominally, a burst at an
decontamination of some chemical agents, often
altitude above 100,000 feet.
accelerated by acid or alkaline solutions or by the
HOOK BOLT--A long bolt that is usually fabricated
presence of hypochlorite.
from round steel stock. Hook bolts come in a variety
HYTROL VALVE--Diaphragm type, fail open,
of diameters and shapes.
seawater pressure-operated control valve that
HORIZONTAL AUDIT--These audits are normally
controls the flow of AFFF solution to systems.
conducted on only one specific area or aspect of the
IGNITION--The act or action of causing a substance
QA Program (re-entry control [REC], welding,
to burn; the means whereby a material starts
training, qualification, or testing). They focus on
burning.
the particular area and do not track a job from start
to finish as the vertical audit does.
IM-143/PD--Identical to the IM-9/PD except in range.
The IM-143/PD indicates gamma radiation dose in
HORIZONTAL LOOP FIREMAIN SYSTEM--
the range of 0 to 600 R.
Consists of two-single fore-and-aft,
cross-connected piping runs. The two individual
IMMEDIATELY DANGEROUS TO LIFE OR
lengths of piping are installed in the same
HEALTH (IDLH)--Any atmosphere that meets
horizontal plane (on the same deck) but are
one or more of the following conditions-flammable
separated athwartships as far as practical.
vapors at a concentration of 10% or greater of the
lower explosive limit (LEL); an oxygen content of
HOSEMAN--A hoseman runs the attack hose from
less than 19.5% or greater than 22%; the presence of
the fireplug to the scene, and you will keep the hose
toxicants above a level that would allow personnel
from getting fouled while fighting the fire and relay
to escape within 30 minutes without impairment or
spoken messages and orders between the on-scene
irreversible health effects.
leader and the nozzleman.
AI-12
