There's Shields and Barriers in the game right? didn't the Shadow Broker have a Barrier than could only be broken by Melee attacks and he was wear I guess his version of a tuxedo.
The Shadow Broker probably had skin as thick as an elephant's. Besides that he was carrying a huge shield that was impenetrable.
There are shields for most classes, the biotic ones have barriers. Shields come from the suit or omnitool I believe. The barrier comes from the biotic him/herself I believe. Feel free to correct me on this.
The logic behind the soldiers being so tough, being able to use all weapons/carry a lot and other soldiery stuff is that they have few abilities. They are the grunts, they rely on muscle. The other classes are more agile, they bruise more easily but they can protect themselves and attack with the tech and biotic tools they have. That is why they are not as strong.
Which might also explain why Vega is as built as he is. It irks me personally but then I suppose there will always be the little things.
Anyways you're right that the armor protects vs temperatures and such, idk about fire and cold tho as you can get lit on fire and freeze blasted lol.
I do not believe that is what they are for, they are for "sahara and antarctica" and not -200 or +200, even in the game I believe most organisms would perish rather quickly no matter the armour. Perhaps the krogan would last a while.
IMO if wearing armor doesn't stop a hailstorm of bullets they why wear full out armor? I'd say f**k that too and wear light-medium armor, who would want to wear a heavy suite and sweat to death if it can't stop bullets?
I once saw a video about some soldiers in Iraq during the war. The humvees they were issued were so crappy that they showed some of them welding steel plates on the doors.
When they asked them why they were doing that, the soldiers explained that the armour it came with was woefully inadequate. With the steel plates in place it still would not stop larger bullets or shrapnel, but at least then it would not tear up everything inside. Instead it would lodge in the first guy it struck..
The point being that even a little armour can make a difference. Perhaps not always or for everyone.
No armour will stop everything, does that mean you should not try to do the best you can? And while you are at it, should it not be your priority to stop bullets, stop your eyeballs from exploding in vacuum and keep you alive, rather than keep you stylish and sexy?