"Give your squad mates weapons even if there is not enough to go around and you need to do without.  Keep most of the ammunition yourself, though.  Your squad mates are good enough shots to take care of any things you encounter, and you can build up and maintain their trust as you re-supply them with ammo.  Be sure to hold on to a flamethrower or torch just in case some of your squad turn out to be infected.  If there is an infected squad member, once you kill him you can regain the gun you gave him." - TEM

"Save your blood tests to use only on yourself, and only when you are having big trust issues in your squad.  Your squad members' transformation into the thing is scripted, so a blood test will return a normal result if you apply it to a squad member before it is time for him to transform as part of the storyline." - TEM

"edge around corners slowly and carefully whenever possible for sniper-type shots...you will see, and have a clear shot at enemies (even bosses) JUST before they can see you. this combination worked particularly well against boss #2 with the flamethrower." - alternatehistory

"When shooting out stacks of crates, just shoot the bottom ones to remove the stack.  The top ones will be taken out too and you'll save precious ammo." - TEM

"When you are with your squad and the cold starts to get to you, it is getting to them too.  However, when you duck inside to warm up you do not need to worry about fitting your whole squad inside.  As long as you warm up they will warm up too." - TEM

"strafe!! and keep strafing! remember to crouch to increase accuracy!" - Realdewd