We all like to have a cosy hot water bottle when we go to bed - it also means for some that the heating doesn’t need to be on. But on every bottle there is a flower symbol - and some people are unaware of what it means.

Hot water bottles have been used since the 16th century and the contents can be very dangerous if they split, the Mirror US reports. The Child Accident Prevention Trust charity has taken to X, formerly Twitter, to highlight what the flower symbol means.

The CAPT said: “This symbol, found on hot water bottles, indicates how old it is. The number is the year it was made, the flower segments represent months and the dots show the number of weeks.

“Old hot water bottles can break and cause serious burns. So, it is advised to regularly check for signs of wear and tear and don’t use hot water bottles that are more than two years old.”

Hot water bottles are made using natural rubber or polyvinyl chloride (PVC) - and commonly come covered in fabric to keep the bottle from touching your skin. But if they get too old they can be prone to breaking - and people, including children can be seriously injured.

X user John Bidder also spoke about the symbol, saying: “Today on a call with carers, we learned an amazing hot water bottle fact! The flower symbol, found on hot water bottles, shows when it was manufactured. Over 2 yrs? Be careful!”

One person said: “Really good information thank you for sharing. I didn’t have a clue about this but have heard some really upsetting stories recently of both adults and children being admitted to hospital with severe burns. Just checked mine now, all good.” Another commented: “You are 100 per cent correct. I have a huge burn scar on my back from a split hot water bottle and it was old. Not something I ever thought about.” And someone else revealed: “Thank you very much, I am going to get mine changed this week!”