You look around. There’s windows high up. There are poles near all of them – probably how they open. Prop ’em up with a pole, take it away and they close. Windows would be important for getting rid of some of the nastier smells, you suppose.
And a thought strikes you. You grab one of the poles, and carry it to another window. Then you use the pole that’s already there and the one you’ve grabbed as something of a ladder.
This would be easier if they had rungs, but you’ve dabbled in acrobatics. Got enough of a sense of balance to get yourself up, holding onto the poles as your feet make their way up the wall.
Not quickly, though. You’re about three-quarters of the way there by the time you hear the loud crash that indicates the demise of your barricade. You start scrambling as best you can to get the rest of the way, but you don’t think you’ll be out before they notice you.
Of course, it doesn’t matter if they notice you – only if they stop you. If you could figure out a way to buy yourself just a little more time… though from up here, your options are rather limited.