Retrofit Heated Seats?

Oddly my 4.6 V8 does not have heated front seats, or at least the switches are not there.

Is it possible to retrofit heated seats?

My existing seats are electric memory seats.

Would anyone know if the wiring is already in place and its just a matter of adding switches?

I am not sure if my existing seats actually have any heating elements in them, is there a way to check?

Thanks