Rick on Twitter: "Quick #electronics tip: You can use a p-channel mosfet and a resistor to add reverse polarity protection to a circuit if a diode doesn't work due to it's voltage
Reverse Polarity Protection – MAlabdali
Over Voltage and Reverse Voltage Protection Circuit
Reverse Polarity Protection - Circuit Cellar
Reverse Polarity Voltage Protection Using P-MOSFET - Electrical Engineering Stack Exchange