[break] out in a sweat

to suddenly start sweating

The intense heat caused everyone in the room to break out in a sweat despite the air conditioning.
After running a marathon, Jane broke out in a sweat as she crossed the finish line.
Waiting for the delayed train on the crowded platform, passengers started to break out in a sweat.
Working outdoors on a hot summer day, the construction crew began to break into a sweat, prompting them to take regular water breaks to stay hydrated.
After walking for hours in the scorching desert sun, Jack finally broke into a sweat, desperately searching for shade.