HEAT STRESS by NxtkM8

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									         HEAT STRESS
          HEAT STRESS

 WHAT  IS HEAT STRESS ?
 WHAT ARE THE CAUSES OF HEAT STRESS?
 HOW DOES IT AFFECT ME?
 WHO ARE PRONE TO HEAT STRESS?
 HOW TO ASSESS HOT ENVIRONMENT?
 HOW TO PREVENT/CONTROL HEAT
  STRESS?
  FACTORS INFLUENCES HEAT STRESS

 AirTemperature
 Humidity -prevention of evaporation
 Movement of air
 Radiant temperature - exposure to sun
 Clothings
 Physical activities
   HOT ENVIRONMENTS
 Gold, iron and steel foundries.
 Manufacture of bricks, ceramics, glass,
  rubber and chemicals.
 Boiler maintenance.
 Bakeries.
 Laundries.
 Kitchens.
 Outdoor operations etc.
          THERMO REGULATION
   BODY PRODUCES HEAT - must be
    dispatched if body temperature is not to
    change.

   BLOOD FLOW INCREASED TO SKIN.

   SWEAT GLANDS - evaporation of sweat.

   ACCLIMATISATION.
       HEAT STRESS DISORDERS
SAFETY PROBLEMS - Lowered alertness & poor
                  coordination/task performance
HEALTH PROBLEMS
 Heat rash (skin wet).
 Fainting (unacclimatised and stand up or stand
  still).
 Heat cramps ( loss of salt from heavy sweating).
 Heat exhaustion (skin moist, feels faint or sick).
 Heat stroke ( skin dry, high temperature,
  confused or unconscious ).
   RISK TO HEAT STRESS
 MEDICALLY UNFIT
 OVERWEIGHT
 SUFFER FROM HEART DISEASE
 ALCOHOL ABUSE
 NOT ACCLIMATIZED
    ASSESSMENT OF HOT ENVIRONMENT

   WBGT (wet bulb globe temperature)-ISO 7243.

     Outdoors : WBGT = 0.7 nwb + 0.2 Tg + 0.1 Ta.
     Indoors : WGBT = 0.7 nwb + 0.3 Tg.

   Underestimates effect of environments of low
    evaporative capacity resulting from low air
    movement and high humidity.

   Limited information about severity of stress and
    cause.
            SWEAT RATE - ISO 7933
        Detail analysis of hot environment
CALCULATION INCLUDES THE FOLLOWING VARIABLES :-
   Duration in minutes.
   Air temperature.
   Globe temperature.
   Wet bulb temperature (psychometric).
   Air velocity.
   Metabolic rate.
   External work.
   Mean radiant temperature. Calculated from globe
                           temp, air temp, air velocity.
               REQUIRED SWEAT RATE
    COMPUTER PROGRAMME IN STANDARD HELP TO
    DETERMINE:
   Exposure times.- excessive core temp or water loss

   Rest duration to remove possibility of risk.
   If modifications are necessary, eg lighter load, shield
    from radiation, increase ventilation, modify clothing,
    drying the air, etc.
   If close monitoring is necessary, eg record heart rate.
   If a medical evaluation is necessary - workers exposed
    to heat stress required a comprehensive medical
    evaluation.
        SAFE SYSTEMS OF WORK
WORK ORGANISATION
 Work in cool part of day.
 Reduce physical effort.
 Shorter exposure.
 Acclimatise workers.
 System for report heat-related discomfort.
WORK ENVIRONMENT
 Erect temporary / permanent cover.
 Breaks in cool areas / creates cool environment
 Barriers, screens.
     SAFE SYSTEMS OF WORK
COOL DRINKING WATER
 Frequent drinking of cool water.


CLOTHING
 Loose reflective clothing & light coloured


HEALTH
 Medical examinations.

								
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