2
Yet, Australia’s Work Health and Safety laws lack a
specified ‘stop work’ temperature, making it challenging
to protect workers solely on an individual basis without
considering their physiological responses [2]. According
to [6, 7], there are inadequacies in the current safety mea-
sures, particularly with the use of the Wet-Bulb Globe
Temperature (WBGT) as a heat stress indicator since the
WBGT system underestimates the stress from restricted
evaporation and through potential measurement errors.
Generally, the “normal” body temperature falls within the
range of 36.1°C to 37.2°C with temperatures exceeding
38°C typically indicating the presence of fever or illness [6,
7]. Furthermore, the human body is ill-equipped to endure
significant fluctuations in core temperature [8]. Severe cases
of hypothermia or hyperthermia can result in permanent
organ damage or even fatality, underscoring the importance
of continuous core temperature monitoring. In addition,
current practices in the mining industry involve recording
body temperature at three distinct time points, which may
overlook temperature peaks in workers.
In the last few decades, several attempts have been made
to non-invasively predict the core temperature (TC) using
single or multiple physiological parameters, such as heart
rate (HR), skin temperature, and heat flux [9, 10, 11, 12].
The Estimated Core Temperature algorithm (ECTemp ™)
was developed to estimate TC based on sequential HR
observations alone using a Kalman filter [13] and a sig-
moid curve [14]. ECTemp ™ has been shown to provide an
accurate indication of thermal strain in military personnel
during moderate-intensity activities (i.e., road march) and
endurance exercise (up to 24 h) in laboratory and field set-
tings [9, 15].
Fatigue can be categorized into three distinct types:
physical, mental, and emotional. Physical fatigue typically
arises from prolonged muscle use, mental fatigue relates
to the inability to maintain focus, and emotional fatigue,
often referred to as chronic fatigue, results from prolonged
exposure to constant stress [16]. While non-chronic fatigue
necessitates subjective measurements or psychological and
behavioral tests for assessment [17], chronic fatigue can be
effectively monitored using HR variability [18].
Gas explosions and air pollution in mines are still com-
mon, posing increasing challenges [19]. Present security
monitoring systems fall short in collectively tracking all
environmental parameters adequately, including air pollu-
tion and chemical gas exposure, alongside miners’ biomet-
rics. Furthermore, due to the absence of clear boundaries
between safe and hazardous workplace environments, rely-
ing solely on a gas sensor proves ineffective in the mining
industry [20].
Health Hazards Monitoring
Prior attempts to collect data from working miners using
goniometers and in-shoe pressure sensors faced difficulties,
primarily due to harsh working conditions that often led
to the failure of externally attached goniometers [21]. In
recent years, companies like Cortex Design and Vandrico
have introduced innovative smart safety helmets equipped
with temperature and humidity sensors, as well as gas sen-
sors capable of detecting methane, radiation, and carbon
Figure 1. Control loop of thermoregulation with internal and external influences on body
and TC [6]
Yet, Australia’s Work Health and Safety laws lack a
specified ‘stop work’ temperature, making it challenging
to protect workers solely on an individual basis without
considering their physiological responses [2]. According
to [6, 7], there are inadequacies in the current safety mea-
sures, particularly with the use of the Wet-Bulb Globe
Temperature (WBGT) as a heat stress indicator since the
WBGT system underestimates the stress from restricted
evaporation and through potential measurement errors.
Generally, the “normal” body temperature falls within the
range of 36.1°C to 37.2°C with temperatures exceeding
38°C typically indicating the presence of fever or illness [6,
7]. Furthermore, the human body is ill-equipped to endure
significant fluctuations in core temperature [8]. Severe cases
of hypothermia or hyperthermia can result in permanent
organ damage or even fatality, underscoring the importance
of continuous core temperature monitoring. In addition,
current practices in the mining industry involve recording
body temperature at three distinct time points, which may
overlook temperature peaks in workers.
In the last few decades, several attempts have been made
to non-invasively predict the core temperature (TC) using
single or multiple physiological parameters, such as heart
rate (HR), skin temperature, and heat flux [9, 10, 11, 12].
The Estimated Core Temperature algorithm (ECTemp ™)
was developed to estimate TC based on sequential HR
observations alone using a Kalman filter [13] and a sig-
moid curve [14]. ECTemp ™ has been shown to provide an
accurate indication of thermal strain in military personnel
during moderate-intensity activities (i.e., road march) and
endurance exercise (up to 24 h) in laboratory and field set-
tings [9, 15].
Fatigue can be categorized into three distinct types:
physical, mental, and emotional. Physical fatigue typically
arises from prolonged muscle use, mental fatigue relates
to the inability to maintain focus, and emotional fatigue,
often referred to as chronic fatigue, results from prolonged
exposure to constant stress [16]. While non-chronic fatigue
necessitates subjective measurements or psychological and
behavioral tests for assessment [17], chronic fatigue can be
effectively monitored using HR variability [18].
Gas explosions and air pollution in mines are still com-
mon, posing increasing challenges [19]. Present security
monitoring systems fall short in collectively tracking all
environmental parameters adequately, including air pollu-
tion and chemical gas exposure, alongside miners’ biomet-
rics. Furthermore, due to the absence of clear boundaries
between safe and hazardous workplace environments, rely-
ing solely on a gas sensor proves ineffective in the mining
industry [20].
Health Hazards Monitoring
Prior attempts to collect data from working miners using
goniometers and in-shoe pressure sensors faced difficulties,
primarily due to harsh working conditions that often led
to the failure of externally attached goniometers [21]. In
recent years, companies like Cortex Design and Vandrico
have introduced innovative smart safety helmets equipped
with temperature and humidity sensors, as well as gas sen-
sors capable of detecting methane, radiation, and carbon
Figure 1. Control loop of thermoregulation with internal and external influences on body
and TC [6]