Steering column slot acting like a heater

Just switched from manual to power steering (and ensuing column switcheroo)

Now, when the engine gets hot, it feels like a supplemental heater is blowing in my lap...the slot on the underside of the steering column is venting engine compartment heated air into the cabin.

Is there something missing (some gasket/collar/plug/something?) that prevents this from happening?

Thanks for any ideas!