Ok,
I normally just use forums for research and I ahve NEVER posted. This problem is so FUNKY and I spent considerably time researching to fix it I thought I owed to everyone to post my thoughts.
I have a higher level knowledge base on the iPhone since I work in IPhone data recovery ..
1. The phone worked FLAWLESS for a year, then I updated to 6.0.1 and the wifi still worked for a short period of time.
2. I bought a Life Proof case at the same time as I did the update. For those dont know this is a fully encased case capable of going underwater 6ft. (may have caused heat issue)
I am almost certain that it is a combination of the the lifeproof case with crappy code on the heat sensor for the wifi.
In a perfect world the wifi would shut off when it gets hot and once it cools would shut back on. In the case of this issue that is not happeneing.
I read everywhere and at first like most I am sure felt this is a SOFTWARE issue. I still believe this, but sometimes software can cause hardware to appeared failed when in actuality it is fine.
If we think back to the old xbox red ring of death this problem was also a wonky heat sensor and could also be fixed by applying heat. Once I thought of it from that angle I figured what could it hurt to try the dryer fix. Maybe it would heat it to the point of resetting the sensor? My phone is 31 days out of warranty and I was not forking over 199 to get a new phone.
So I removed the phone from the lifeproof case, Applied heat from a hair dryer to the back of the phone near the earphone jack for about 3 minutes and then waite for the phone to cool enough to handle and turned it back on. WIFI up and running now. It has been about an hour.
I have no intention of putting the lifeproof case back on, or and kind of enclosure like that until the new os release just to try and keep the phone cool as I live in FL.
Hope this helps
Jacqui