Heat Stress Flashcards
(27 cards)
Where can you find the Heat Stress instruction?
OPNAVINST 5100.19F
What is heat stress?
A combination of air temp, thermal radiation, humidity, airflow, workload, and health conditions that may stress the body as it attempts to regulate body temp.
What equipment do we use to conduct heat stress survey?
WBGT or AHSS
What does WBGT
Wet-Bulb Globe Temperature-Meter
What does the WBGT measure/read?
Radiant and convection heat to or from the body.
Where on board the ship may heat stress occur?
Machinery spaces, laundries, sculleries, galley, incinerator rooms, flight deck, and steam catapult rooms.
What conditions can elevate a heat stress?
Hot and humid climate, arduous physical tasks, steam and water leaks, boiler air casing leaks, missing or deteriorated thermal insulation, and ventilation system deficiencies.
What factors reduce physical stamina?
Dehydration, lack of sleep, illness, use of medication, drugs, alcohol, and presence of atmospheric contaminants such as combustion gasses or fuel vapors.
How many WBGT are we required to have on board?
2
How often is Heat Stress training conducted?
Annually, and when reporting on board.
What is the position or placement when hanging the dry bulb thermometer?
May be in or out of the ventilation air stream but must be hung at least two fee from any supply ventilation terminal/opening.
What do you use to hang the dry bulb thermometer?
Non-heat conducting material, such as plastic tie wrap or string.
Does the Dry Bulb thermometer require calibration?
No
What if the hanging dry bulb thermometer is found inaccurate?
Validate by aligning the etch mark with the freezing point (32* F).
How often does the watchstander record reading on locally prepared paper log?
- Every 4 hours for manned spaces below 90*
- Every hour for manned spaces over 90*
As a heat stress surveyor, when shall the first measurement be conducted in the space?
After the WBGT has been in the space 5 minutes.
When is a heat stress survey conducted?
When permanent mounted dry-bulb thermometer reaches or exceeds:
-PHEL Curve I through III
=> 100* watch/work length is 4 hours or less.
=> 90* watch/work length is more than 4 hours
-PHEL curve IV through VI
= 85* heat injury occurs,
Prior to conducting ECC drills (if drills exceed 3 hours).
CO determines heat stress may occur.
Follow-on survey.
When do we conduct follow-on surveys?
DB temp increases by more than 5* from the previous survey, or a return to normal watch/work time is desired.
What is the recovery time for personnel reaching exposure limit?
Twice the exposure time or 4 hours, whichever is less.
When is Time Weighted Mean used?
In especially hot environments where reduce stay times have been imposed on watch/work standers.
What affects or reduces your stay time or exposure limits and how much?
Presence of stacked gasses, and reduces by to 2/3 stay time.
What are the symptoms of stack gasses?
Eyes watering/burning, difficulty breathing, tingling or numbness of the tip of the tongue, nose, fingertips, or toes, generalized sensation of mild intoxication without consumption within past 24 hours.
How does the surveyor determine the stay time?
By using the PHEL time table (curve).
What does PHEL stand for?
Physiological Heat Exposure Limit.
