2. Information Input & Processing
Cognitive System Model
Human Factors
Energy Expenditures (Rest & Physical Activity)
Heat Stresses
Heat Disorders & Health Effects
Heat Exhaustion & Heat Stroke
3. Information Input and Processing
Information Theory:
Some times called cognitive psychology, cognitive
engineering, and engineering psychology.
Information is defined as the reduction of uncertainty.
The occurrence of highly certain events do not convey
much information (such as fasten seat belt sign). But the
occurrence of highly unlikely events convey more
information (such as high temperature warning in a car).
4. The fasten seat belt sign conveys less information because it is
expected. Although it is an important message, the importance
is not directly considered in the information definition.
Because this message comes on every time the car is started, it
contains little (or no) information in the context of information
theory.
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9. Basal Metabolic Rate
◦ BMR is rate of energy expenditure fasted, rested and supine
conditions in thermoneutral environment.
Resting Metabolic Rate (RMR) is rate of energy expenditure
when at rest but not basal (> BMR).
◦ BMR proportional to BSA, after age 20 2% & 3% per
decade in women and men, respectively
◦ BMR represents largest fraction of TEE (Total Energy
Expenditure)in Physical work.
10. Influence of Body Size
◦ Differences in body size usually expressed in
terms of body surface area (BSA).
◦ From 20-40, average values BMR are 38
kcal/m2 per hour for men and 36 kcal/m2 for
women.
◦ Lower BMR in women can be attributed to
woman’s larger percent body fat & smaller
muscle mass.
11. Energy expended during weight-bearing
activities increases proportional to body mass.
There is little relationship between body mass
and energy expended during non-weight-
bearing activities.
12. Average daily Total Energy Expenditure
estimated to be 2900 – 3000 kCal for males,
and 2200 kCal for females 15-50 y.o.a.
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18. The type of clothing worn must
be considered
Prior heat injury predisposes an
individual to additional injury.
20. Occurs when the body's system of temperature
regulation fails and body temperature rises to critical
levels
This condition is caused by a combination of highly
variable factors, and its occurrence is difficult to
predict
Heat stroke is a medical emergency
