New study suggests we've been wrong about how sweat forms
The findings may have practical applications that could help us manage extreme heat events better in the future.
If you’ve been sweltering through this summer in Canada, you’re not alone. Many regions are experiencing intense heat. If you're living in one of these areas, sweating, body’s natural cooling mechanism, has probably been a common occurance.
How we thought sweat forms
Many of us picture sweat as beads forming on the skin, but new research published in the Journal of the Royal Society Interface challenges this.
Instead of droplets, researchers found sweat rises through pores, saturating and pooling before merging into a thin, flat layer across the skin.
How the study was conducted
The researchers observed six healthy adult participants who sat in comfortable recliners while wearing specialized suits designed to heat and cool the body. The researchers focused on the participants' foreheads, measuring how sweat forms and evaporates as temperatures change.
What they discovered
As the body heated, sweat didn’t bead on the surface. Instead, it accumulated in the pores, and only then overflowed, spreading across the skin in a connected film. After cooling, the sweat evaporated rapidly, leaving behind a salt residue.
When the heating process resumed, the remaining salt helped the sweat absorb into the skin faster, allowing it to reappear more quickly the second time around.
A diagram illustrating how sweat formed the first time in the study. (Jose et al., J. R. Soc. Interface, 2025)
Why this matters
Despite decades of research, there’s still much to learn about how sweat spreads and evaporates. This new study bridges earlier research by examining both pore-level behaviour and larger skin surface dynamics.
The findings may have practical applications that could help us better manage extreme heat events in the future.
By better aligning with how the body naturally cools, future clothing and gear could improve our ability to cope with warm weather.
Header image: file photos from Canva Pro.