You could try killing the power to your device. Assuming you are unable/unwilling to physically disconnect the device, you should run (as root):
iwconfig wlan0 txpower off. I would then wait 10-15 seconds to make sure whatever hardware issue has caused the problem has been stopped, then:
iwconfig wlan0 txpower auto.
Or, you can simply run rfkill and block/unblock your device. . (as root)
rfkill block wifi, followed by
rfkill unblock wifi. This second option should be faster, since you only need to wait 2-3 seconds between commands, as opposed to 10-15 seconds. In fact, on my machine, I don't need to wait at all, although I suspect this depends on your WiFi hardware.