Scalding means extremely hot, hot enough to burn skin or other tissue. When water is scalding, it's far too hot to touch safely: think of steam rising from a just-boiled kettle or water straight from a pot on the stove. A scalding shower can happen when someone flushes a toilet while you're showering and suddenly all the cold water disappears from the pipes, leaving only dangerously hot water.

The word comes from the injury it can cause. To scald someone means to burn them with hot liquid or steam. Cooks need to be careful with scalding oil or boiling water. Parents test bathwater before putting young children in because scalding water can cause serious burns in just seconds.

You'll also see scalding used to describe harsh criticism that feels like it burns. A teacher might deliver a scalding response to a student who was disrespectful, or a restaurant might receive a scalding review from an angry customer. In this sense, the words feel hot enough to hurt.

The key is extreme heat: warm water is comfortable, hot water is uncomfortable, but scalding water is actually dangerous.