yep its a temp sensor light
if the motor controller or one of the motors overheats that light will turn on or flash depending on what stage of overheating it is in. Generally it is accompanied by another light designating which system is overheating. Such as the drive motor light or pump motor light. Either motor light will be lit along with the temp light to let you know which system is overheating. Also the drive or pump speed will be slowed down to let the system cool off, when it is cool the lights should turn off.
Of course if you have a short somewhere it may not be overheating but still triggering the system falsely.