UKEng, Dora - In the UK you'd be protected for undertaking a good samaritan act. You wouldn't get sued if you were genuinely trying to help someone. I think a couple of people have tried to sue their rescuer, but none have been successful.

Interestingly, in some countries there is a 'duty of rescue' law, which means that all citizens have a duty to try and help someone who is injured or in danger, and they can be held libel if they don't.