Questions about bottled breast milk

Mr

After pumping, how long can breast milk sit out (unrefrigerated)? I read online 6-8 hours, unless it’s warm then 4 hours? After the 6-8 hours, can I put it in the fridge for 24 hours? I would just hate to put it in the fridge and warm it up then have LO only drink a tiny bit, then have to dump the rest...I’m new to bottle feeding, as I mainly just breastfeed. So any tips or advice would be great!