"Grew hot" is a phrase that can be used to describe an increase in temperature, intensity, or anger. However, there are several synonyms that can be used to convey the same meaning, such as "heated up," "flared up," "boiled over," "became incensed," and "fumed." Each of these alternative phrases can be used to add more depth and complexity to the description of a situation or emotion. By utilizing synonyms, we can enhance the clarity and impact of our writing and create a more evocative experience for the reader.