熔炉a container that is heated to a very high temperature, so that substances that are put inside it, such as metal, will melt or burn
People who work with furnaces in a steel factory need to wear protective clothing. 钢厂里在熔炉边工作的人都需要穿防护服。
This room's like a furnace (= is very hot)! 这个房间热得像熔炉！