WI-FI not detecting any networks

My phone has fell twice till date.both times after that wifi was working fine.

but suddenly i dont know what happened my phones wifi has stopped detecting networks.and now it is not able to detect any wifi networks i have also tried at my friends place and at many more hotspots but no luck.bu i found a video on youtube named chill fix so i gave it a try.SO WHEN I KEEP MY PHONE IN FREEZER FOR 20 MINUTES,WI-FI WORKS FINE UNTIL THE PHONE GETS BACK TO NORMAL TEMPERATURE.OTHER THEN THAT ITS NOT ABLE TO SEARCH OR JOIN ANY NETWORKS,I HAVE TRIED JOINING NETWORKS MANALLY.

PLS HELP ME TO FIGURE OUT THE PROBABLE CAUSE...??

the worse part is i have bought this phone from america and right now i have been using it in india.