From nhs site
What do I need if I'm formula feeding away from home?
If you need to feed your baby away from home, take with you:
- a measured amount of formula powder in a small, clean and dry container
- a vacuum flask of hot water that's just been boiled
- an empty sterilised feeding bottle with cap and retaining ring in place
The vacuum flask doesn't need to be sterilised, but should be clean, and only used for your baby. The boiling water should kill any bacteria present in the flask.
If the flask is full and sealed, the water will stay above 70C for several hours.
Make up a fresh feed only when your baby needs it. The water must still be hot when you use it, to destroyany bacteria in the formula powder.
Remember to cool the bottle (with the lid on) under cold running water before you feed it to your baby.
Alternatively, you could use a carton of ready-to-feed liquid formula when you're away from home.
What if I need to transport a made-up feed?
If it isn't possible to follow the advice above, or if you need to transport a feed (for example, to a nursery),prepare the feed at home and cool it for at least one hour in the back of the fridge.
Take it out of the fridge just before you leave and carry it in a cool bag with an ice pack, and use it within four hours. If you don't have an ice pack, or access to a fridge, the made-up infant formula must be used within two hours.
If made-up formula is stored:
- in a fridge–use within 24 hours
- in a cool bag with an ice pack–use withinfour hours
- at room temperature–use withintwo hours