By Zoe Tabary
LONDON, Sept 22 (Thomson Reuters Foundation) – What Christian Clot remembers most vividly from his days in Iran’s boiling Dasht-e Lut desert was having to stay completely still for 12 hours a day – or die.
“It was so hot I had to lie down behind some rocks between 8 a.m. and 8 p.m. Staying in a tent was too dangerous as it would have instantly overheated,” he recalled.
Clot, a French-Swiss explorer, is testing the limits of human endurance, including to worsening temperature extremes.
In the Iranian desert and on three other 30-day expeditions alone in the world’s harshest climates, he has explored what impacts extreme weather might have on people, both physically and mentally.
“Most studies on the human body have been done in labs rather than in real settings,” he told the Thomson Reuters Foundation. “I wanted to experience what you can’t find in scientific journals.”
If planet-warming emissions continue to rise at their current pace, three in four people in the world will face deadly heat by the turn of the century, according to a study published in the journal Nature Climate Change in June.
Emily Y.Y. Chan, a professor of public health at the Chinese University of Hong Kong, expects heatwaves to become not just more frequent but also longer by the end of the century.
That could lead to a range of worsening health problems – including some unexpected ones, such as more malnutrition.
COOLING ABILITY
For his experiment with heat, Clot chose Iran’s Dasht-e Lut desert, where the daytime temperature can reach nearly 60 degrees Celsius (140 degrees Fahrenheit).
“I knew I could die within hours of exposure to such high temperatures,” he admitted.
Each day, Clot collected data, including his heart rate and body temperature, and carried out tests to assess the heat’s impact on his mental abilities, including his decision-making and memory.
Although his scientific team are still analysing the results, Clot said the biggest challenge was extreme physical and mental tiredness.
“Every movement I made was slower and demanded more effort,” he explained. “I was conscious of the threat surrounding me but found it extremely challenging to stay attentive at all times.”
Georges Benjamin, executive director of the American Public Health Association, thinks Clot’s struggle with excessive heat is hardly unique.
“The average human doesn’t tolerate heat well,” he said – but some can cope better than others.
“The human body functions like the radiator of your car: your ability to cool yourself down depends on a range of factors like your age, your capacity to sweat, whether or not you’re taking any medication,” he said.
For those unable to regulate their body temperature effectively, the spectrum of heat-related illness ranges from simple sunburn to severe dehydration and heatstroke, which can be life-threatening, he added.
