(1) The simplest level of the entire game. Move quickly, and you can grab every single powerup here. Unless your armor is really low, ignore the steam and fire jets until the last leg of the timed run. Come straight out of the starting blocks and move straight ahead down the hallway, nabbing 4 derm patches en route. When you reach the T-crossing (at the med kit), turn left. You have reached a square catwalk with another hall on the far side of the square opposite the one you just exited.
(2) In the upper left corner (where you headed when you turned left) are a shotgun and 2 shells.
(3) Move to the upper right corner for 3 flame thrower canisters, nabbing the pulse rifle magazine on the way.
(4) Run to the lower right corner for a grenade, pulse rifle, and pulse rifle magazine. You will pass an acid vest (which you will need by now) on the way, at the T-crossing formed by the second hallway.
(5) Now head to the lower left corner (nabbing the grenade en route). Here you will find 2 med kits and the mondo powerup of the level, the first 200-point body armor of the game.
(6) Head back for the unexplored hallway, staying on the left side of the walkway (up against the railing) so you don't get fire-jetted. Once into the hall, if you're fast, you'll find a med kit and 3 derm patches just as the counter winds down.