I would wager the reason your ferns died is more due to the lack of drainage than due to the heat. Lack of drainage is a surefire way to kill plants, not to mention introduce a whole slew of issues. That said, for your current application, the heat is unlikely to be an issue. However, UTH heat does tend to dry out soil pretty significantly, so I wouldn't pick something that needs constant moisture like a bromeliad.

If it were me, I would try something something from the hoya family like a hoya curtisii and perhaps pepperomia. Both of these are non-toxic, tend to drape / hang down, and do not require a ton of watering. Indeed, dry periods seem to help them out.

Also, your first pick of a spider plant wouldn't be a bad choice either.