I tried the freezer method as somebody explaned in this forum and it worked for me.
switch off the phone
wrap with a kitchen towel (tissue)
insert into a freezer bag
put rice into the bag to cover the phone
suck out air from the bag as much as you can and seal it
wrap again with a kitchen towel
place inside the freezer (where there is no frost) for 30 mins
take out and leave the phone for about 30 -40 mins until it comes to the room temperature
plug into the itunes and restore