Sky got out of his cage and was threatening the two "free bird" males on top of their cage. In addition to his aggressive actions, he was holding his wings away from his body (when our female conure does this, we call it the "cobra maneuver"). I netted him and put him back in his cage with his female, Sun == and he's still keeping that same stance. What is up? He had no trouble flying while he was out, so they're not broken -- since he's not used to that, could his wings just be sore?
(My g/f just sprayed him with the water bottle and he stopped, so I guess he was overheated. So I guess this is an advice post now instead of a question post!)
My budgies also do that when I have them outside on a hot day. It gets really hot here in Texas during the summer, so I've decided to keep them inside and they haven't held their wings out since then. My chickens also do this so I do think it's a way to keep themselves cool when they're hot!
When hot budgies will hold their wings out from their bodies and even breath with their beaks open, if at all possible have them in a shaded and quiet area, remember also the water will heat up very quickly in this weather and bacteria will grow. Change the water regularly and offer baths, misting, place wet towels over the cage and have a fan blowing onto the towels slowly, this will help cool them down.
Budgies will also stand like this when extremely frightened sometimes. But I am sure it is the heat in this instance.