hey apple
how long does it takes when my iphone 4s grayed wifi fixed using a hairblower???
iPhone 4S, iOS 8.4, white
Apple is not here. This is a user-to-user technical support forum.
As one of the common causes of WiFi failure is that the chip overheated, I'd guess that using a hair dryer on the phone (never a recommended procedure) will never fix it. Make an appointment at the Genius Bar at your local Apple Store to have the phone evaluated.