
Some fire services advise not to charge your phone overnight at all.
Apple is issuing a warning for people who fall asleep holding their phone while it's charging.
The tech giant says its iPhones should only be charged in a 'well-ventilated area' like on a flat table and not on a duvet.
iPhones heat as they charge, so they have the potential to cause burns or even start fires.
Some fire services advise not to charge your phone overnight at all.