Katie Piper warns about the risks of old hot water bottles, once made of copper or brass, causing burns. Despite being now made of rubber, they can still pose dangers when aged. Piper, who founded the Katie Piper Foundation after experiencing burns herself, emphasizes the importance of checking expiration dates to prevent accidents.

The foundation advises against using worn-out bottles, suggesting covering them with cloth, avoiding boiling water, and filling only two-thirds. Every UK hot water bottle features a ‘flower wheel’ indicating its manufacturing date.

While old hot water bottles carry risks, Penkala’s rubber design revolutionized their safety, offering warmth without the dangers of metal predecessors.