Toyota 2015 Prius Owner's Manual page 396

3-5. Other interior features
Seat heaters
The seat heaters can be used when
■
The "POWER" switch is in ON mode.
When not in use
■
Turn the seat heater off.
PRIUS_OM_OM47A17U_DVD_(U)
Heats the left front seat
Heats the right front seat
The indicator light comes on.
Press the button again to turn off
the seat heater.
The indicator light turns off.
3
: If equipped
375