Wearing white clothing won't make you cooler in the heat, researchers confirm

The common assumption that wearing white or light-colored clothing is cooler when it's hot is false. It doesn’t matter if someone wears white or black clothes, according to a study by professor of exercise physiology Maria Hopman and a team of scientists during the Vierdaagse Marches in Nijmegen. The research team had an average group of male and female hikers alternate between white and black T-shirts.

The hikers took a temperature pill every day before they started their march, with which their body temperature could be measured throughout the day. A skin button was also stuck on their back and upper arm, containing a sensor that kept track of their skin temperature throughout the day. “These measurement techniques have not been around for very long, and that is why such a study has never been done before,” said Hopman. According to her, partly because it is increasingly very hot, it is important that it has now been scientifically established that the color of your clothing doesn’t matter. “This way, we can give people even better advice.”

Hopman came up with the idea for the study after the very hot edition of the Vierdaagse Marches in 2022 when the organizers had to cancel one day of the walking event due to the extreme heat. “We then received a lot of questions about which clothing a hiker could best wear. Everyone thought white, but desert peoples, for example, almost always wear black. We wanted to know which was best equipped for heat. It doesn’t matter, turns out.”

The weather wasn’t extremely hot during this year’s Vierdaages, Hopman admits. On Tuesday and Wednesday, thermometers climbed above 25 degrees in the afternoon, but not a single day has hit 30 degrees. “That is why we are going to repeat the study during a Vierdaagse with tropical temperatures,” said the professor.