Unfortunately if you’ve tried the rice trick (see above) and your phone still won’t turn on, you’re unlikely to get it working again. It might be worth having it looked over though. For iPhone and Samsung users, take it to The Apple Store or Samsung Experience Store where they’ll be able to advise you on what to do and may be able to provide you with a replacement handset. Alternatively, take your phone in to your service provider store (Vodafone, EE etc.) or retailers like the Carphone Warehouse. They may be able to give you an idea of how likely it is you’ll get your phone working again, where to send it if so, and what to do if not.