BMW i3 seat weight - around 32 lbs if I remember correctly.
3 series power leather seat - about 90lbs each
You only need cooled seats when you get leather - no issue on fabric usually. Leather is a terrible material in my opinion
In the olden days the lower folks used to rid in their horse carriages on leather seats outside in the rain, while the kings and queens where sitting on nice plush fabric seats inside in comfort.