Luca with temperature sensor

ESA astronaut Luca Parmitano wearing a temperature sensor on his forehead for the Circadian Rhythms experiment in 2013. Luca had just returned from his five-month stay on the International Space Station as part of the Volare mission and researchers were still collecting data on how his body reacts to spaceflight.

The Circadian rhythms experiment measures an astronaut’s temperature and melatonin, a hormone linked to sleep. The readings are measured continuously using a new, patented sensor that monitors temperature without impractical thermometers.

The findings will help in finding out how to rest effectively and be alert when most needed, a skill that many would benefit from, especially astronauts who need to be ready for spacecraft dockings at irregular intervals.