Heat Stress Monitoring Tools for Hot Factory Work Areas Malaysia
Meta Description: Discover suitable instruments for monitoring heat stress, air temperature, humidity, radiant heat and airflow in hot factory work areas in Malaysia.
Malaysian factories may have work areas that become extremely hot during production or maintenance activities.
Common examples include:
Boiler rooms
Furnace areas
Compressor rooms
Generator rooms
Metal-roof warehouses
Commercial kitchens
Laundry facilities
Outdoor loading areas
Factory rooftops
Poorly ventilated production areas
A normal thermometer measures only air temperature. It does not show the combined effects of humidity, radiant heat, airflow and direct sunlight.
For a more complete assessment, factories may need a WBGT heat stress meter together with other environmental instruments.
What Is a WBGT Heat Stress Meter?
A WBGT meter measures or calculates Wet Bulb Globe Temperature.
This index combines several environmental factors that affect heat exposure, including:
Air temperature
Humidity
Radiant heat
Direct sunlight
Natural air movement
WBGT provides more useful information for hot-work environments than air temperature alone.
Why Factory Maintenance Teams Need Heat Monitoring
Heat monitoring helps maintenance and safety teams investigate:
Complaints about excessively hot work areas
Poor ventilation
Failed exhaust fans
Heat produced by machinery
Hot-air recirculation
Inadequate cooling
High humidity
Direct radiant heat
Conditions before and after ventilation improvements
Measurements also provide objective data when deciding whether engineering controls or work-practice changes are needed.
1. Boiler Room Heat Checks
Boilers, steam pipes, pumps and other hot equipment can increase both air temperature and radiant heat.
Useful instruments include:
WBGT heat stress meter
Temperature-humidity meter
Anemometer
Infrared thermometer
Thermal imaging camera
A WBGT meter evaluates the work environment, while a thermal camera helps locate hot surfaces and damaged insulation.
2. Furnace and High-Temperature Production Areas
Air temperature alone may not represent conditions near a furnace.
A worker can experience significant heat even when standing several metres from the equipment because of radiant energy.
A WBGT meter with a globe sensor helps account for this radiant heat.
A thermal imaging camera can separately identify:
Hot machinery surfaces
Insulation problems
Heat escaping from equipment
Unexpected hot zones
3. Compressor and Generator Rooms
Compressors and generators release heat while operating.
Poor ventilation may cause:
High room temperature
Equipment overheating
Reduced efficiency
Frequent alarms
Shorter component life
Uncomfortable maintenance conditions
Use:
Temperature-humidity data logger for long-term monitoring
Anemometer for ventilation airflow
Thermal camera for equipment hot spots
WBGT meter for the work environment
4. Metal-Roof Warehouses
Metal-roof warehouses may become extremely hot during the afternoon.
Conditions can vary between:
Ground level
Upper storage racks
Areas near the roof
Doorways
Central warehouse zones
Ventilated and unventilated areas
Several measurement locations may be required to understand the actual conditions.
5. Outdoor Factory Maintenance
Outdoor maintenance may include:
Rooftop HVAC work
Cooling-tower inspection
Pipe maintenance
Loading-bay work
Tank inspection
Solar-system inspection
External electrical work
Direct sunlight adds radiant heat, making outdoor WBGT different from ordinary shade temperature.
Measurements should be taken where the work is actually performed.
6. Hot Production and Packaging Areas
Factories may experience localised heat around:
Ovens
Dryers
Steam equipment
Cooking lines
Shrink-wrapping machines
Heated tanks
Moulding machines
Process exhausts
Portable heat monitoring helps compare conditions at different workstations.
WBGT Meter vs Temperature-Humidity Meter
InstrumentWhat It MeasuresBest ApplicationWBGT meterCombined heat-stress indexHot work areas and heat-risk screeningTemperature-humidity meterAir temperature and relative humidityGeneral environmental checksInfrared thermometerOne surface temperaturePipes, motors and machineryThermal imaging cameraSurface-temperature patternLocating hot equipment and insulation problemsAnemometerAir velocityVentilation and fan checksData loggerConditions over timeOvernight or full-shift monitoring
A temperature-humidity meter is useful, but it does not replace a WBGT meter when radiant heat is significant.
Surface Temperature Is Not Air Temperature
An infrared thermometer may show that a boiler pipe is 100°C or a metal roof is extremely hot.
That does not mean the surrounding air is at the same temperature.
Similarly, a thermal camera shows surface-temperature patterns, not the heat-stress index experienced by a worker.
Each instrument answers a different question.
How to Perform a Basic Factory Heat Survey
Step 1: Identify the Hot Work Area
Select the actual location where employees perform their tasks.
Step 2: Record the Work Condition
Note:
Equipment operating status
Work activity
Direct sunlight
Protective clothing
Ventilation
Measurement time
Step 3: Position the WBGT Meter
Place it at a representative working height and location.
Avoid placing it directly beside an air-conditioning outlet unless that is the condition being investigated.
Step 4: Allow the Sensor to Stabilise
Globe temperature and other sensors may require time to respond to the environment.
Step 5: Record Several Measurements
Conditions can change throughout the day.
Repeat measurements during:
Morning
Midday
Afternoon
Peak production
Maintenance shutdown
Before and after ventilation changes
Step 6: Compare Different Areas
Check both the suspected hot zone and a reference area.
Step 7: Investigate the Cause
Use additional instruments to determine whether the problem involves:
Poor airflow
Hot machinery
Damaged insulation
High humidity
Direct sunlight
Inadequate exhaust
Hot-air recirculation
Where Should the Meter Be Placed?
Place the meter:
Near the worker’s actual position
At a representative height
Under the same sunlight or shade condition
Away from accidental contact with hot equipment
Where air movement is representative
Where it will not be affected by an unrelated cooling outlet
A reading taken at the entrance may not represent conditions beside a boiler or furnace.
Why Measurement Time Matters
Factory heat conditions may change because of:
Outdoor weather
Production load
Equipment startup
Ventilation schedule
Door opening
Afternoon solar heat
Shift pattern
Cleaning activity
A single reading may miss the hottest part of the day.
For changing environments, a data-logging model may provide more useful information.
Using an Anemometer to Check Ventilation
If WBGT or room temperature is high, use an anemometer to check:
Exhaust airflow
Supply airflow
Air movement near workers
Ventilation openings
Fan performance
Hot-air discharge
Low airflow may result from:
Failed fan
Dirty filter
Blocked duct
Incorrect fan speed
Closed damper
Poor ventilation design
Using Thermal Imaging to Locate Heat Sources
A thermal imaging camera may help locate:
Uninsulated steam pipes
Damaged boiler insulation
Hot motors
Overheated electrical equipment
Hot roof surfaces
Heat escaping from furnaces
Abnormal equipment temperature
This allows maintenance teams to identify physical sources contributing to the hot work environment.
Using a Data Logger for Long-Term Monitoring
A temperature-humidity data logger is useful when:
The area becomes hot only at certain times
Complaints occur during one shift
The problem happens overnight
Ventilation switches on and off
Management needs a temperature trend
Several areas need comparison
A data logger does not measure WBGT unless it is specifically designed for that function.
Possible Factory Heat-Control Actions
After identifying the cause, possible actions may include:
Improving mechanical ventilation
Repairing failed fans
Cleaning filters
Redirecting hot exhaust
Insulating hot surfaces
Installing radiant-heat shields
Providing shade
Reducing hot-air recirculation
Creating cooler recovery areas
Adjusting work scheduling
Monitoring conditions continuously
The appropriate action depends on the equipment, workplace and heat-risk assessment.
How to Choose a Heat Stress Meter
Consider:
WBGT Measurement
Confirm that the instrument provides WBGT rather than only temperature and humidity.
Globe Sensor
A globe sensor is important where radiant heat is present.
Indoor and Outdoor Modes
Select a meter suitable for indoor work and outdoor conditions with direct sunlight.
Data Logging
Useful for full-shift or multi-day monitoring.
Alarm Function
A programmable alarm can alert users when a selected level is reached.
Display
A clear display helps technicians read several parameters on site.
Battery Life
Ensure the instrument can operate throughout the monitoring period.
Mounting
Tripod mounting may help position the meter consistently.
Common Factory Heat-Monitoring Mistakes
Avoid:
Measuring only air temperature
Using an infrared thermometer as a WBGT meter
Taking readings only at the room entrance
Moving the meter before it stabilises
Ignoring radiant heat
Ignoring humidity
Measuring in shade when employees work in direct sun
Taking only one reading
Ignoring equipment operating status
Comparing areas at different times without recording the difference
Assuming WBGT alone explains every heat-related complaint
Recommended Heat Monitoring Instruments
RequirementRecommended InstrumentAssess heat-stress conditionsWBGT heat stress meterMeasure temperature and humidityTemperature-humidity meterRecord conditions over timeTemperature-humidity data loggerCheck ventilation airflowAnemometerMeasure hot surface temperatureInfrared thermometerLocate machinery heat patternsThermal imaging camera
Heat Stress and Environmental Monitoring Instruments Malaysia
MTM Precision supplies instruments for factory heat monitoring, boiler rooms, warehouses, compressor rooms, outdoor maintenance and high-temperature production areas.
Our range includes WBGT heat stress meters, temperature-humidity meters, anemometers, data loggers, infrared thermometers and thermal imaging cameras.
We can help customers select the correct instrument according to whether they need to measure worker heat conditions, ambient temperature, airflow or equipment surface temperature.
Contact MTM Precision
MTM Precision Sdn. Bhd.
Showroom & Service Centre
No. 29-1 & 29-2, Jalan Bandar 18,
Pusat Bandar Puchong,
47160 Puchong, Selangor, Malaysia
🌐 Website: www.mtmpre.com.my
📧 Email: mtmpre@yahoo.com
📱 WhatsApp: +6016-660 7346
31 Aug 2026
