Dictionary form to ask if someone wants something


I can't find much about it but I found an example to illustrate it:

> 温めますか
>
> Do you want it heated?
> [weblio](https://ejje.weblio.jp/sentence/content/%22%E3%81%BE%E3%81%99%E3%81%8B%22/2)

I don't understand how the dictionary form can have the meaning 'to want' and
what is the difference with てもらいたいですか, てほしいですか, etc.




Based on what I know,

Instead of saying "want" (ーたい), it's more polite to say "shall I" (ーましょうか).

If you want to ask someone if they want something heated, it would be polite
to say this:

温めましょうか?

