A "boiler suit" is a one-piece garment that covers the whole body, similar to a jumpsuit. It is typically made of durable fabric and is often worn by workers in industries like construction or engineering for protection and comfort. Full definition
Not really doing any heavy manual work over here, but I do enjoy wearing boiler suits, because they take the stretch of putting together an outfit, off of my brain. (alwaysjudging.com)
These perceptions include the thinking that all careers involve working offshore wearing boiler suits and hard hats, that it is dirty and physical work — and an industry dominated by men. (educationbusinessuk.net)