Just found a good tip on CC to use during the return flight from Tahiti:

The only complaint with ATN is the check-in at the Papeete airport, although I don't think it's just ATN. Basically you stand in a long snaking line for a good hour or more. It's unbelievably hot, humid, and sticky.

One tip someone gave me that turned out to be a good one is that there IS an air-conditioned section at the Papeete airport. You just have to go upstairs into the buffet restaurant area. You don't have to buy a full meal. You can even just get a drink and sit down at a table. It's up the flight of stairs that starts in the middle of the restaurant area on the main level.