1.
steam bath, sauna
A bath or room filled with steam for bathing or relaxation. Also used figuratively to describe an extremely hot and humid environment.
Usage
蒸し風呂 literally means "steaming bath." In everyday speech, it is very commonly used as a simile with のよう or みたい to describe unbearably hot and humid places, such as crowded trains, rooms without air conditioning, or outdoor spaces during the humid Japanese summer.