why is my phone overheating

[AC Question]

Plugged in a USB 2.0 wireless 802.11n and turned on Bluetooth and instantly it said device overheating can only use telephone and nothing that uses data and then a lite where flashlight is and won't go off that is where the most heat is

 

[mhinc]

Plugged in a USB 2.0 wireless 802.11n and turned on Bluetooth and instantly it said device overheating can only use telephone and nothing that uses data and then a lite where flashlight is and won't go off that is where the most heat is

Not understanding what you mean by plugging in a USB 2.0 wireless 802.11n to your device?
Does your phone not already have WIFI?
What device is this? Is it new? Do you have a lot of apps running in the background?