We have a 10 months baby with us, can we take a metal flask like this with us in hand luggage ?
On Heathrow's webpage they say it is not allowed but then from where are we going to get hot sterilized water for baby on the plane?
This answer to a question five years ago said it's allowed.
Reference to Heathrow's rules.
Can I carry liquid baby food, prepared milk, soya milk, rice milk or sterilised water through security?
Yes, if you are travelling with a baby or infant you can carry a reasonable amount of liquid and liquidised food for the baby or infant infant for your journey. To assist security screening, please do not carry these items in a flask. Spare supplies must be packed in your hold baggage.
Edit Both answer's sound very helpful, could you also illustrate how we can get hot water while in lounge as well please? Planning to be there three hours in advance + if airplane delays?