Heated up milk

If you have frozen milk and you put it in the fridge to thaw and pull it out and warm it a little to mix with oatmeal cereal is it ok to put it back in the fridge to use again a little later? Basically just is it ok to restore warmed up milk?

**edit: I should have clarified a little better like I warm it and mix part of it with oatmeal cereal and then there's some plain milk leftover**