To Heat Something Up
To Warm Something Up
transitive verb, ichidan verb
You know that the kanji 温 means warm, and this verb is related. It means to heat something up or to warm something up. It's all about you doing something to another object to make it hot, like putting it in the microwave.
The kanji reading is the same as 温かい. As long as you know that word, you should be able to associate that reading with this word.
Please don't heat that bowl in the microwave.
Before I go to bed, I like to heat up milk and drink it.
Kombu seaweed releases its sweet flavor when it’s soaked in water and heated up.