Abstract: Methods and apparatus for implementing over-temperature fault protection in wearable devices and other electronic devices are disclosed herein. An example apparatus includes a voltage source; a thermistor bias network to, when enabled, output a thermistor voltage; an over-temperature determiner to enable the thermistor bias network; and, when the thermistor voltage corresponds to a temperature above a maximum temperature threshold, output a fault; and an isolation transistor to couple the voltage source to a system; and when the over-temperature determiner outputs the fault, decouple the voltage source from the system.