Black globe temperature
Accurately measures environmental radiant heat (including direct sunlight and radiant heat from hot machinery)
±0.2°Caccuracy
Workplace Heat Stress Alert System
Heat Safety Guardian
See heat hazards
before they hit.
Calculates the WBGT heat index in real time and triggers audible-visual alarms and LINE alerts the moment a threshold is exceeded.
Solar-powered with NB-IoT connectivity, so no wiring is needed on site.
Heat Safety Guardian is a heat hazard alert system developed in-house by YenProtek. It calculates the WBGT heat stress index in real time and, when limits are exceeded, triggers an on-site audible-visual alarm and a LINE notification.
5environmental sensors
Air temperature, humidity, black globe temperature
wind speed, wind direction
wind speed, wind direction
3alert layers in sync
On-site alarm, LINE push notification
cloud event log
cloud event log
0power or network wiring
Solar-powered
NB-IoT wireless transmission
NB-IoT wireless transmission
24-hour continuous monitoring
Round-the-clock visibility
into environmental data and heat risk
into environmental data and heat risk
Global trends
Heat at work:
rules keep getting stricter.
The Wet Bulb Globe Temperature (WBGT) index is the heat-stress assessment index used in the international standard ISO 7243:2017. The International Labour Organization (ILO), the World Health Organization (WHO) and the World Meteorological Organization (WMO) have also called on employers and governments to establish workplace heat action plans.
More and more countries are setting specific rules that use WBGT readings as the basis for taking action. Requirements vary by country, so always follow the local regulations in force.
- Singapore Hourly The Ministry of Manpower requires hourly WBGT monitoring for outdoor work, with rest scheduled by the readings
- Qatar 32.1°C Work must stop when the workplace WBGT exceeds this level
- Japan 28°C Since June 2025, work at WBGT 28°C or above requires heat-illness reporting and response procedures set up in advance
How Heat Safety Guardian helps
- Calculates WBGT on site in real time to track changes in heat exposure
- Triggers light-and-sound alarms and LINE notifications the moment a custom threshold is exceeded
- Stores every alert and the environmental data at that moment in the cloud for easy review
- Alert thresholds can be set to local regulations, guidelines or site needs
Requirements vary by country and industry; always confirm your actual obligations against the local regulations in force. This system supports monitoring, alerting and record-keeping, but it does not replace statutory workplace environmental measurements.
Precision Sensing
Beyond air temperature:
the heat your body actually feels.
Simultaneously measures air temperature, humidity, black globe temperature, wind speed, and wind direction, and displays the WBGT heat stress index in real time.
- Air temperature
- Humidity
- Black globe temperature
- WBGT heat stress index
Air temperature
High-sensitivity digital sensing with fast response and low error
±0.5°Caccuracy
Humidity
Anti-condensation design for stable operation in high-humidity environments
0–95% RHmeasurement range
Wind speed and direction
Assesses microclimate heat dissipation and can assist facility ventilation control
0–70 m/swind speed range
WBGT heat stress index
The system computes WBGT in real time and proactively issues alerts when readings become abnormal, supporting effective heat hazard management
Real-timecalculated from air temperature, humidity and black globe temperature
Three-Layer Synchronized Alerts
Threshold exceeded:
three channels alerted at once.
When monitored readings reach your custom alert thresholds, the system simultaneously activates on-site warnings, remote notifications, and cloud logging.
Heat Safety Guardian Measures conditions and calculates WBGT
Alert threshold Customized to your site
Synchronized alerts Alarm, LINE, cloud log
-
On site: instant audible-visual alarm
A high-decibel, high-brightness audible-visual alarm is triggered immediately on site, alerting workers to heat hazard risk.
-
On the go: LINE push notifications
The system simultaneously sends alerts to managers via LINE push notifications, making it easy to monitor site conditions remotely.
-
In the system: cloud data and event records
Environmental data and event records from before and after each alert are retained automatically for later review, tracking, and auditing.
Alert records are management records.Every alert and the environmental data at that moment are kept in the cloud, so adjusting working hours and scheduling rest breaks is backed by evidence.
No Wiring Needed
Wherever the site is,
set it up there.
The standard kit includes a solar power module and an NB-IoT communication module, so no additional power or network cabling is required. Installation is quick and easy, making it ideal for temporary construction sites or work areas where equipment is frequently relocated.
Cloud Command Center
Heat hazard command center:
every area at a glance.
Integrated AIoT monitoring makes hard-to-detect heat hazard risks visible in real time.
Many sites, one screen.
- Centrally manage multiple sites and monitor each zone's risk level in real time
- Present heat hazard indicators in a visual interface for more intuitive reading
- Display complete WBGT, temperature, humidity, black globe temperature, wind speed, and wind direction data
- Switch freely between an all-site overview and individual device details
- Support multiple languages and refresh anytime for the latest data
- Accessible from smartphones, tablets, and computers
API Integration
Feed the data into your existing systems.
An API is available to integrate monitoring data into your existing management systems.
WBGT31.6 °C
Black globe temp.45.2 °C
Wind speed1.4 m/s
Illustrative screen
Standard Kit
Ready out of the box,
expandable when you need it.
A standard kit with flexible expansion modules.
Standard Hardware Package
- Heat Safety Guardian main unit
- NB-IoT communication module
- Solar power module
- Audible-visual alarm
- App and cloud management system
- LINE alert push notifications
Optional Expansion Sensors
Beyond core heat hazard monitoring, additional sensors can be added to suit your site:
- Air quality (PM2.5/PM10)
- Decibel noise sensor
- Rainfall Sensor
- UV index sensor
* The brand, appearance, and model of the audible-visual alarm may vary by supply batch; the actual shipped contents shall prevail.
Warranty & Service
Buy with confidence.
Use with ease.
As simple as a phone or home appliance: use it straight out of the box, and if it fails under warranty, we replace it.
One-Year Warranty
For one year after purchase, we cover any fault in the product itself, and an extended warranty is available. Actual warranty terms are subject to your quotation.
Replaced, Not Repaired
If it fails under warranty, there's no repair trip and no waiting: we ship a replacement right away, so heat hazard monitoring never stops.
No Wiring Needed
Solar-powered with NB-IoT wireless transmission, so even temporary sites can be set up quickly.
Designed and Made in Taiwan
Designed and manufactured by our team in Taiwan, with local technical support and repair service.
Track Record & Applications
Workplace safety IoT:
we've built it for real.
Frequently Asked Questions
What is the WBGT heat index?
WBGT (Wet Bulb Globe Temperature) is an index that takes into account environmental factors such as air temperature, humidity, wind speed, and radiant heat to assess the risk of heat stress that hot environments pose to the human body. It is also one of the key criteria the Ministry of Labor uses to classify heat hazard risk levels. Heat Safety Guardian calculates WBGT in real time from air temperature, humidity, and globe temperature, and proactively issues alarms when readings become abnormal.
How do different countries regulate work in hot conditions?
There is no single global rule. WBGT is the heat-stress assessment index used in the international standard ISO 7243. Singapore requires hourly WBGT monitoring for outdoor work, with rest breaks scheduled according to the readings; Qatar requires work to stop when the workplace WBGT exceeds 32.1°C; and since June 2025, Japan has required employers to set up heat-illness reporting and response procedures for work at WBGT 28°C or above. Requirements vary by country and industry, so always follow the local regulations in force.
How are on-site workers and managers notified of alarms?
Heat Safety Guardian uses a three-tier synchronized alarm mechanism: on site, high-decibel, high-brightness audible and visual alarms alert workers immediately; at the same time, the system pushes alarms to managers via LINE so they can keep track of site conditions remotely; and in the cloud, environmental data and event records from before and after each alarm are retained for later review and auditing.
Does installing Heat Safety Guardian require electrical wiring?
The standard kit includes a solar power module and an NB-IoT communication module, so no additional power or network cabling is required. Installation is quick and easy, making it ideal for temporary construction sites or work areas where equipment is frequently relocated.
Can I customize the alert thresholds?
Yes. Alert thresholds can be customized to local regulations, guidelines or site needs. When a reading reaches a threshold, on-site alarms and LINE notifications are triggered at the same time.
Can it be used indoors in factories or in semi-outdoor areas?
Yes. Besides outdoor work such as construction sites, road paving, and elevated rooftops, it is also suitable for high-temperature workplaces such as steel mills and high-temperature industrial plants.
Can alert records be used for audits?
The system automatically retains environmental data and event records from before and after each alert for later review, tracking, and auditing.
What if it breaks?
It comes with a one-year warranty, and an extended warranty is available. If the product fails during the warranty period, there's no need to send it in and wait for repairs: we ship you a replacement right away so your heat hazard monitoring is back up and running as quickly as possible. After the warranty expires, units can be returned to our factory for repair. Actual warranty terms are subject to your quotation.
Specifications
Environmental Sensing
Air temperature
- Measurement Range and Accuracy
- -30 ~ 80°C，±0.5°C
- Notes and Technical Features
- High-sensitivity digital sensing with fast response and low error
Humidity
- Measurement Range and Accuracy
- 0 ~ 95% RH，±5%
- Notes and Technical Features
- Anti-condensation design for stable operation in high-humidity environments
Black globe temperature
- Measurement Range and Accuracy
- -40 ~ 100°C，±0.2°C
- Notes and Technical Features
- Accurately measures environmental radiant heat (including direct sunlight and radiant heat from hot machinery)
Wind Speed
- Measurement Range and Accuracy
- 0 ~ 70 m/s（±3%）
- Notes and Technical Features
- Assesses microclimate heat dissipation and can assist facility ventilation control
Wind Direction
- Measurement Range and Accuracy
- 0 ~ 360°（±3°）
- Notes and Technical Features
- Assesses microclimate heat dissipation and can assist facility ventilation control
WBGT heat stress index
- Measurement Range and Accuracy
- Calculated from air temperature, humidity, and black globe temperature
- Notes and Technical Features
- The system computes WBGT in real time and proactively issues alerts when readings become abnormal, supporting effective heat hazard management
System
Connectivity
NB-IoT communication module
Power
Solar power module No power or network wiring needed
Alerts
On-site audible-visual alarm LINE alert push notifications Cloud data and event records
Platform
App and cloud management system Viewable on phones, tablets and computers
Expansion Sensors
Air quality (PM2.5/PM10) Decibel noise sensor Rainfall sensor UV index sensor
Data Integration
An API is available to integrate monitoring data into your existing management systems
Manufacturing & Service
Designed and manufactured by our team in Taiwan Local technical support and repair service
Warranty
One-year warranty Faulty units replaced with new ones during warranty Extended warranty available Actual terms subject to quotation
Applications
Ideal for outdoor work and high-temperature workplaces that are prone to heat and localized microclimate effects and require stronger heat hazard management:
- Construction and infrastructure
- Road paving works
- Elevated rooftop work
- Outdoor construction zones
- Steel and high-temperature industrial plants
Regulations Mandate Measures. What Truly Matters Is Protecting Every Worker.
High-temperature work risks should not go unnoticed until someone feels unwell. With real-time monitoring and proactive alerts, managers can spot risks early and arrange rest and protection in time, so every hardworking outdoor worker can go home safely.