Why does my Android phone lose Wifi?

When using Bluetooth, a few Android phones lose connectivity to WiFi and revert to their carrier's Internet connectivity because they use the same hardware for both Wifi and Bluetooth. We know the following phones have this issue: Nexus 4, Nexus 7 2013 Edition, Moto X, Moto G. Feel free to let us know if your phone experiences this issue and isn't in the list above.