加热 (jiā rè): to heat

The weather was too cold, so my mom heated the milk until it was warm and then handed it to me.

When making a cake, you need to first heat the butter until it melts, and then mix it with the flour.

The leftover food has been in the fridge for two days; you'd better heat it before eating.

In the lab, we use an alcohol lamp to heat the liquid in the test tube and observe its changes.