Measuring Skin Temperature in Sports Science: The Grant Thermistor Standard

Skin temperature is one of the most informative signals in sports science. It shapes thermoregulation, cardiovascular stress, perceived exertion, sweating behaviour and, ultimately, endurance performance. To measure it well during exercise, researchers need a sensor that stays accurate while an athlete sweats, moves and changes environment. For decades, that sensor has been the contact thermistor.

The Grant EUS-UU thermistor probe and the SQ16 data logger are a pairing many university laboratories reach for. They are used in exercise-physiology teaching, environmental-chamber studies, military heat assessments and sports-clothing evaluation, part of the wider measurement work Eltek supports across research and life-science laboratories.

Why skin temperature matters

Skin temperature tells a researcher how well an athlete is managing heat. During exercise it reflects the balance between the heat the body produces and the heat it can shed through the skin. Read alongside core temperature, heart rate and sweat rate, it helps explain performance, fatigue and safety.

That is why skin temperature appears so often in applied physiology:

• It indicates an individual’s ability to stabilise core temperature during heat exposure.
• Elevated, unstable or regionally divergent skin temperatures can signal increased heat strain.
• The data support evaluation of sports-clothing systems, equipment load and heat-acclimation training.

Capturing those signals cleanly, at several body sites at once, is a measurement problem. It needs a sensor that is accurate, low-mass and robust, and a logger that can record many channels together.

The sensor: Grant EUS-UU thermistor probe

The Grant EUS-UU is a surface thermistor probe designed specifically for physiological skin-temperature measurement. Its design is built around the demands of exercise research:

• Measurement range: −50 °C to +150 °C
• Accuracy: ±0.1 °C
• Cable: slim, low-mass VL-series cable, 3.1 mm diameter
• Termination: bare-wire, for flexible connection to research-grade data loggers

The compact sensing head and low thermal mass are what make it suitable for the skin. A low-mass probe equilibrates quickly to skin temperature, so it tracks rapid warm-ups, interval exercise and external cooling or warming without lagging behind the real reading. The slim cable sits comfortably under clothing and across joints, and the bare-wire termination lets a lab wire the probe into the channel layout a study needs. For how thermistors compare with other sensor types across demanding conditions, see our guide to selecting the right temperature probe.

Paired with the SQ16 multi-channel data logger, the small sensor head and flexible cabling suit the 4-site, 6-site and 14-site temperature arrays used in thermoregulation, endurance testing and sports-clothing research. One logger captures the whole array together, on a single time base.

Proven in the research literature: MacRae et al. (2018)

The case for thermistors is not only practical, it is documented. The systematic review by MacRae et al. (2018) examined the sensors used across the sport, exercise and physical-activity literature, and two findings stand out:

1. The most common sensor type. Thermistors were used in 89 of 172 reviewed studies, making them the dominant sensor type in the field.
2. Grant is the most-cited manufacturer. Of the studies that reported a sensor brand, Grant Instruments (Cambridge, UK) was cited more often than any other company, in 29 studies. This reflects widespread trust in the quality, robustness and accuracy of Grant probes, particularly the EUS-series sensors.

These findings reflect why thermistors, and Grant sensors in particular, became the default choice: the practical reasons behind that preference, low thermal mass, multi-site flexibility and stability during exercise, are covered above.

A proof case: the UK Military Heat Illness Clinic

One of the most demanding applied examples comes from the UK Military Heat Illness Clinic, which uses Grant skin thermistors during its Heat Tolerance Test (HTT) (House, 2021). In this protocol, participants walk at 60% VO₂max in a 34 °C, 44% RH environmental chamber, while continuous skin-temperature readings from multiple sites help determine whether the individual can achieve thermal balance.

The logic that governs a heat-tolerance decision in that clinic, reading multi-site skin temperature to judge whether a person can hold thermal balance under load, is exactly the logic a sports scientist applies to an endurance athlete.

These insights map directly onto endurance-sport preparation: marathon and ultra-running heat strategies, triathlon kit assessment, and athlete-safety protocols all rest on the same skin-temperature evidence.

How UK universities use Grant probes in teaching

Across the UK, around 70 universities offer undergraduate and postgraduate degrees in fields such as sports science, sport and exercise science, sport and exercise physiology, sports coaching, sports therapy and sports rehabilitation. These programmes routinely include laboratory modules in exercise physiology, environmental physiology, sports biomechanics, performance testing, and sports medicine and rehabilitation.

Grant data loggers and probes, including the EUS-UU skin-temperature sensor, give students hands-on experience with the same research-grade equipment used in published studies. They support teaching across:

• Pre-exercise baseline assessment. Students record resting skin-temperature values before exercise, learning about homeostasis and individual variability.
• Monitoring during exercise. On treadmills, cycle ergometers or field-based endurance tasks, skin-temperature data help students understand thermoregulation and heat balance.
• Heat-stress testing. Environmental chambers or simulated heat sessions let students observe changes in skin temperature, sweat rate and physiological strain.
• Cold-exposure studies. In cold-room protocols, Grant probes are used to analyse skin-cooling rates, peripheral vasoconstriction and rewarming responses.
• Injury rehabilitation. In sports-therapy modules, students assess local skin temperature over injured tissue to explore inflammation, circulation and recovery.

Through these sessions, students gain familiarity with research-grade equipment, skills in data interpretation and thermal-response analysis, and experience that aligns directly with elite-sport, clinical and research careers. Grant equipment helps prepare the next generation of sport scientists, physiologists, therapists and performance analysts.

Applications in sports-clothing and endurance research

Beyond teaching, the EUS-UU thermistor and SQ16 logger are well suited to applied research programmes:

• Sports-clothing evaluation. Thermal mapping under technical fabrics; compression-garment and base-layer testing; analysis of breathable, reflective, moisture-wicking and insulating materials.
• Environmental training programmes. Monitoring heat-acclimation progression; cold-weather clothing studies for ultra-endurance and mountaineering; dual-stressor studies combining heat with altitude or humidity.
• Endurance-performance preparation. Heat-tolerance screening; sweat-distribution mapping for cooling strategies; pre-race garment and environmental-strategy optimisation.

In each of these, the value is the same: accurate, multi-site skin-temperature data that hold up under the real conditions of exercise.

A benchmark instrument for sports science

The Grant EUS-UU thermistor probe is one of the most widely used skin-temperature sensors in sports-science education and postgraduate research. Supported by decades of use across universities, by the findings of systematic review, and by real-world application in military heat-tolerance testing, the EUS-UU probe together with the SQ16 data logger remains a benchmark instrument for studying thermoregulation, clothing performance and human endurance across diverse environmental conditions.

If you are equipping or upgrading a sports-science lab, the Eltek team can help you specify the right probe-and-logger setup for your teaching and research.