(1) There are 8 or 9 (yes--it varies) derm patches to grab on this powerup level. Other than that, the prime goods here are 2 body armors, 4 seismic survey charges, and a single grenade. The pulse rifle is the quickest crate-opener due to its long reach and fast firing rate. Hit the ground running and move out of the entranceway. The pair of crates on the left hold a seismic and a shotshell.
(2) Wind your way around to 2 opposite-facing crate-and-barrel barricades. Blow both stacks and grab the goods: on the right are 2 patches, the auto-map (do take the extra second to grab it--this item makes navigation quite a bit easier), and a shotgun shell; to the left are 1 OR 2 derm patches (this seems to vary randomly--the extra patch is there approximately once out of every 3 or 4 loads) and a flame thrower canister. To acquire that extra derm patch, keep reloading this level until it shows up and then try to make a successful circuit.
(3) Now run down the LEFT corridor and blow the next pair of crates (1 on either side) for a derm patch and pulse rifle magazine. Keep moving and ignore a second pair of crates (empty!).
(4) You will want to take your next right but first dash straight ahead past the junction into the very short corridor extension and blow 3 crates for another derm patch, a seismic charge, and the body armor.
(5) Now backtrack slightly to that right turn. Just around the corner and to the right is an opening with 4 crates: one pulse rifle magazine, a derm patch, and a med kit. In the second of the 2 crates you pass on your right as you move forward are night vision goggles, but you don't really need them here and you also don't really have the time.
(6) Bypass the corridor to your right; the 2 crates just past it contain a 9mm pistol and med kit. The next crate (on your left) is empty. Take the next right and blow the crate on your immediate left for another derm patch. If you need grenades or pulse rifle ammo keep moving to the end of this corridor for a single grenade, a pulse rifle, and 2 magazines.
(7) Now dart out of this corridor offshoot and stay right around an inverted U-shaped bend (the crate at the bend holds a med kit, and the one on your immediate left after making the turn holds the final patch).
(8) If you didn't grab the pulse rifle with grenade and magazines back there you, have just enough time to either continue forward for 3 crates holding a flame thrower and 2 fuel canisters or do an about face and then turn left and go straight down to the end for 2 seismic charges, a med kit, and body armor. If you are quick around the corners you can exit with all the derm patches and seismic charges unless you go for the pulse rifle goods instead. Just by way of being complete, if you take the right corridor where the crate-and-barrel barricades are you will reach an empty crate on the right and one holding a med kit farther on down to your left.