Unlike Disney, Universal for the most part has almost all areas air conditioned. However, I'll try to think if there's some that might not be...
For Universal
- At least in the beginning, is Men in Black, but it's shaded and once you get inside it's fully air conditioned (which is almost all of the queue).
- ET is not air conditioned in the beginning as well, but once again shaded and should be able to quickly gain access inside and is fully air conditioned inside (like MIB).
- Shrek is outside period, some of it shaded, some not, however it's a show, so when they let people inside, it's a lot of guests at a time.
- The Simpsons is outside period and some parts are shaded and some are not.
For Islands of Adventure
- The Dragon Challenge is partially outside, but basically the part that's outside is you walking to the attraction, the time you're waiting you'll be in an air conditioned environment.
- Flight of the Hippogriff is outside and shaded (however I haven't been there for long waits so I do not know who it is once the wait is really long).
- Hogwarts Express is partially outside and inside.
- Jurassic Park is outside period and is not air conditioned, but shaded and a water ride.
- Popeye is outside, but once again shaded and also a water ride.
- Dudley Doo Right is partially an outside queue and inside queue and once again a water ride.
At the top of my head those are the attractions I can think of in which you might for a partial time, or full time be waiting outside in an un-air conditioned environment, everything else I'm pretty sure is a fully air conditioned environment.
If you want a place to chill that's air conditioned and that is not too crowded, as I suggested in another post, you can always go to Discovery Center in the Jurassic area. We like to chill near the dinosaurs in the corner and sit while leaning against the rocks. Or another place I recently discovered, but not really tried out, is a place that's at the exit of Horror Make Up Show. You exit the show and there is a hallway which people enter into, before going into a gift shop. Except for the flood of people who would come out of the show every half hour, or so, I would imagine the hallway to be empty and it is definitely cool in there.
Like everyone said, it's kind of hard to not find a place that's air conditioned, but typically places are flooded with people, or it might be hard to find a place to sit, however, with these places you'll be sitting on the ground, but at least you'll be able to relax in the comfort of air conditioning and not too many people hovering over you.