Thermal imagery provides new opportunities to study concepts and processes in
biology. Examples include using infrared (IR) cameras in educational activities
to explore energy transfer and transformation in human physiology, animal
thermoregulation, and plant metabolism. The user-friendly and visually
intuitive nature of IR technology is well suited to the study of rapidly
changing temperatures on biological surfaces, due to such energy transfers. IR
cameras are therefore potentially helpful pedagogical tools for approaching
the Energy and Matter crosscutting concept in the Life Sciences discipline of
the Next Generation Science Standards.
Key Words: Infrared cameras; biology education; NGSS.
Thermal imaging technology is based on the fact that all objects
emit thermal radiation. The wavelength of the radiation depends
on the temperature of the object – for typical temperatures on
Earth, predominantly in the infrared (IR) range. An IR camera
detects the radiation emitted from an object’s surface. Together
with assumptions of surface emissivity, the object’s temperature
can be calculated and displayed on a screen numerically and along
a selected color scale – for example, where warmer surfaces are rendered red and colder surfaces blue (Vollmer & Möllmann, 2017).
Thermal imaging is used for a multitude of applications, including
detecting heat leakages in buildings, avoiding overheating of electronic components, surveillance, and aerial observation of any
remaining hot spots after forest fires. In medical science, applications include detection of increased body temperature due to infection or poor blood circulation due to diabetes (Lahiri et al., 2012).
Apart from industrial and medical use, thermal imaging has also
become increasingly popular in displaying nocturnal animal behavior in wildlife films, such as the National Geographic production
Night of the Lion.
Entry-level handheld IR cameras are durable, intuitive to use,
and becoming increasingly more affordable. The FLIR C3 model
that we used in our experiments costs ~$700. Less expensive IR
camera versions such as FLIR ONE and Seek Thermal can be
directly connected to a smartphone or tablet computer. Due to
the versatility of thermal imaging, IR cameras are gaining momentum as pedagogical tools across all levels of science education. To
date, the technology has been adopted mostly in physics and chemistry educational practice (e.g., Vollmer et al., 2001; Xie, 2011;
Haglund et al., 2015), but there are also compelling opportunities
for the learning of various concepts and principles in biology. In
the sections below, we describe a range of life science content areas
where the use of IR cameras can enhance students’ biology learning. We also suggest how the activities can be mapped onto specific
learning objectives at different grade levels in the Next Generation
Science Standards (NGSS).
IR Applications in Human Physiology
Kubsch et al. (2017) describe an experiment in teaching human
physiology in which students use an IR camera to observe local temperature increases of muscle tissue during exercise. While sitting in
the “wall seat” position with thighs perpendicular to the wall,
increases in temperature on the surface of students’ legs are visible
after 40–50 seconds. In other experiments concerning the human
somatosensory system, an IR camera can help students explore
how the sense of touch relates to temperature measurements. For
instance, at room temperature, metal feels colder than wood or plastic, due to differences in the thermal conductivity of different materials (Haglund et al., 2015). Similarly, a hand that is moved from
cold water to tepid water feels warm, but a hand that is moved from
hot water to the same tepid water feels cold (see Figure 1); hence, the
exercise demonstrates that the sense of touch is not a reliable thermometer (Jeppsson et al., 2017). In addition, one’s skin feels cool
when stepping out of a shower. Using an IR camera, one can observe
The American Biology Teacher, Vol. 81, No. 7, pp. 520–523, ISSN 0002-7685, electronic ISSN 1938-4211. © 2019 National Association of Biology Teachers. All rights
reserved. Please direct all requests for permission to photocopy or reproduce article content through the University of California Press’s Reprints and Permissions web page,
www.ucpress.edu/journals.php?p=reprints. DOI: https://doi.org/10.1525/abt.2019.81.7.520.
TIPS, TRICKS &
The Pedagogical Potential of
Infrared Cameras in Biology
• JESPER HAGLUND,
KONRAD J. SCHÖNBORN