heat up
phr. v..phr. v.. to make something warm or hot, or to become hot yourself.
phr. v.. to increase the temperature of an object or environment; can be used transitively (to warm something) or intransitively (to become warm).
I need to heat up my soup in the microwave.
The room started to heat up as soon as the afternoon sun hit the large windows.
As the political debate began to heat up, both candidates abandoned their prepared remarks and engaged in a series of sharp personal attacks.
often used for food or physical spaces, but can also describe a situation becoming more intense.
point out that 'heat up' is more common than the simple verb 'heat' in casual conversation, especially regarding food.
I will hot up the coffee.I will heat up the coffee.'hot' is an adjective, while 'heat' is the verb form required for this phrasal verb.