Boilermakers perform physically demanding and dangerous work. They often work outdoors in all types of weather, including extreme heat and cold. Dams, boilers, storage tanks, and pressure vessels are usually large. Therefore, boilermakers often work at great heights. When working on a dam, for example, they may be hundreds of feet above the ground. Boilermakers also work in cramped quarters inside boilers, vats, or tanks that are often dark, damp, and poorly ventilated.