rags on racks with adequate ventilation for
All trash cans in living and berthing spaces
should be provided with tight-fitting covers and
be cleaned inside and out when they become
soiled. The use of plastic liners is recommended.
Air all bedding, including mattresses, outdoors
at frequent intervals.
Use all mattresses with covers, otherwise they
become permeated with body grease, dirt, and
Mattresses properly protected with impervious
covers that have been used by personnel with
highly infectious diseases must be disinfected
by wiping with approved disinfecting solutions;
unprotected mattresses may be autoclave with
facilities that are available and the particular
construction materials (e.g., cotton ticking) can
withstand heat and pressure. If no facilities for
autoclaving unprotected mattresses are available
or the materials cannot be autoclave, survey the
mattresses and destroy them by burning.
Clean, renovate, or replace mattresses that are
dirty or in a poor state of repair as soon as
HEATING, VENTILATION, AND
The major objectives of heating, ventilation,
and air conditioning are to maintain physical
fitness, mental alertness, fighting ability, and the
general well-being of personnel ashore and afloat.
This should include consideration for the stresses
of frequent watches, prolonged cruising, and
battle or general quarters situations. The design
and maintenance of environmental control
systems should ensure useful productivity and
recovery from undue physical stress rather than
thermal comfort alone.
In addition, environmental control systems
must ensure that the air in confined spaces
contains no harmful components and has
sufficient quantities of oxygen.
Special use areas, such as selected Medical
Department spaces and those containing equip-
ment and material that require individually
controlled surroundings, must be designed to
guarantee optimum mission performance under
variable environmental conditions.
The problems encountered in maintaining
optimum habitability aboard naval vessels
can be realized if we consider the many
factors involved. The heating, ventilation, and
air-conditioning systems must be designed for a
wide range of climatic conditions ranging from
arctic to tropical. The structural integrity of the
ship must be preserved and penetration of
watertight structures kept to a minimum. In spite
of this, fresh air and heat must be provided to
various compartments often far removed from the
source of supply.
These problems are further complicated by
the lack of uniformity of ventilation or heat
demands in the various parts of the ship. Spaces
exposed on one or more sides to the prevailing
weather may have a high rate of heat gain or
loss. Inside spaces may be subject to the effects
of wild heat, that is, uncontrolled or waste heat
generated by machinery, boilers, galley stoves and
ovens, and the like. Thus adjacent compartments
may vary to such an extent that one requires
heating while the other needs cooling.
STRESS AND STRAIN
The thermal (heat or cold) stress of any
working situation is the combination of all
factors that result in a gain or loss of body heat
or that prevent the bodys regulatory mechanism
from working properly. Environmental phys-
iologists use the term stress to designate
the force or load acting upon the biological
system and the term strain to designate the
resulting distortion of the biological system.
Thermal stress factors are heat, cold, humidity,
radiation, air movement, and surface tempera-
ture. Thermal strain manifests itself in specific
cardiovascular, thermoregulatory, respiratory,
renal, endocrine, and other responses that differ
from accepted norms.
Thermal stress has been categorized as
acceptable when a person is able to com-
pensate without undue strain or unacceptable
when a person is unable to compensate and
incurs excessive strain. Thermal strains have been
categorized as those interfering with work
performance and safety and those with more
overt manifestations such as heat rash, heat
cramps, heat stroke, heat exhaustion, or freezing
DRY-BULB TEMPERATURE (DBT)
That temperature measured with an alcohol-
in-glass thermometer whose bulb is kept dry and
shielded from radiation.