Weightlessness increases astronauts' body temperature

January 8, 2018, Charité - Universitätsmedizin Berlin

Astronauts float weightlessly in space, and the condition of weightlessness is something many would love to experience. However, in addition to producing both physical and psychological stress, a trip into space affects the core body temperature of astronauts. Researchers from Charité - Universitätsmedizin Berlin have observed that body temperature rises during weightlessness, and that, even at rest, astronauts' body temperature is approximately 1°C above the normal value of 37°C (98.6°F). Results from this study have been published in the journal Scientific Reports.

The researchers found that the experienced a type of persistent fever. During exercise, the astronauts' body often exceeded 40°C (104°F). The team of researchers, led by Prof. Dr. Hanns-Christian Gunga (Deputy Director of the Institute of Physiology), used forehead sensors to measure the core body temperature (the temperature of the internal body and brain) of astronauts on the International Space Station. The researchers found that this increase in temperature developed gradually over 2.5 months, eventually reaching approximately 38°C (100.4°F).

"We developed a new technology that combines a skin surface temperature sensor with a heat flux sensor, and which is capable of measuring even minor changes in arterial blood temperature," explains Prof. Gunga. Using this technology, the researchers measured the astronauts' core body temperature before, during and after their stays on the ISS, taking readings both at rest and during exercise. "Under weightless conditions, our bodies find it extremely difficult to eliminate excess heat. The transfer of heat between the body and its environment becomes significantly more challenging in these conditions," explains the space medicine specialist. In space, sweat evaporates more slowly than on Earth, which explains why astronauts were found to overheat particularly quickly during exercise tests performed on the ISS.

Excessive fluctuations in core body temperature can impair both physical and cognitive performance, and can even be life-threatening. It is hoped that these new findings will have positive implications for the health and well-being of astronauts during future long-term space missions. Prof. Gunga adds: "Our results also raise questions about the evolution of our optimum : how it has already adapted, and how it will continue to adapt to climate changes on Earth."

Explore further: Keeping the rhythm in space

More information: Alexander C. Stahn et al, Increased core body temperature in astronauts during long-duration space missions, Scientific Reports (2017). DOI: 10.1038/s41598-017-15560-w

Related Stories

Keeping the rhythm in space

June 15, 2017

Space is an inhospitable environment for the human body but we adapt remarkably well. Within hours, the brain adjusts to the lack of an up or down, as if floating is all it has ever known. Now researchers are learning how ...

Feeling the rhythm

October 26, 2016

Many astronauts play instruments, and some have even made music in space. Few have danced in space, though, perhaps because crew members find it difficult to tap their toes when weightless. Or it could be that spending time ...

Who sweats more: Men or women?

February 24, 2017

Sex differences in heat loss responses are dependent on body size and not sex, meaning that larger individuals sweat more than smaller ones during cycle exercise in warm and tolerable conditions. That's what research published ...

Recommended for you

Making stars when the universe was half its age

January 18, 2019

The universe is about 13.8 billion years old, and its stars are arguably its most momentous handiwork. Astronomers studying the intricacies of star formation across cosmic time are trying to understand whether stars and the ...

Saturn hasn't always had rings

January 17, 2019

One of the last acts of NASA's Cassini spacecraft before its death plunge into Saturn's hydrogen and helium atmosphere was to coast between the planet and its rings and let them tug it around, essentially acting as a gravity ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.