Yes on the back of 4119 or 9119 seats there is an air duct to hook up a portable fan (or an expensive portable AC unit) to cool down the driver. It is simply a hole that goes through the seat.
Here is the rear of a 9119 carbon/kevlar seat

You can also see the integrated back mount. When tied to the roll cage, the seat is so stiff that you can shake the entire car with it.