The most prevalent cause of wilt is a simple lack of water, although it can also be a symptom of certain diseases.
A hot, dry breeze can cause some plants to wilt even if they are sitting in water due to stress. The only solution is to move the plant to a more protected place, away from hot, direct wind. Because this is not always possible (and even less convenient) the best course is often to do nothing. Eventually, the weather will change, and the plant will cool down and recover on its own.