Does Toyota recommend "Engine block heater" on Prius ??

Prodigyplace the heater is for the hybrid battery and not for my feet, anybody knows the wattage for it?

 

The hybrid battery is heated and cooled by cabin air. There is a fan to help direct air flow of the conditioned cabin air through the battery pack.

 

Check this tread New Prius (2017) enhanced with a hybrid battery heater? | PriusChat
There are 2017 Prius that have liquid cooled hybryd batteries here in Canada, hence the heater

 

I stand corrected on the heater but see nothing about liquid cooling. It it likely a blanket type heater.