You wear a spacesuit in hard vacuum and stay alive but you go outside in a dust storm and get LUNG DAMAGE.
It makes no sense.

Spacesuits Just Work because they have to. If they didn't then people would not be out there working and living in these conditions.

What this mod does:
1) Poor Air Quality Hazards: Dust Storms, Sand Storms, etc.
If you are wearing a full spacesuit (suit, pack, helmet) BEFORE you are exposed to the hazard, you have FULL IMMUNITY.
No warning beeps, no possibility of lung damage. Doesn't matter how much airborne resistance you have...
If you are NOT wearing a full suit when first exposed to the hazard it is too late. Putting a suit on after will not prevent lung damage.
(It's just the way the system works. I have no control over this.)

2) Toxic Gas, Extreme Toxic Environment, Microbial, Corrosive Gas:
If you are wearing a full spacesuit (suit, pack, helmet) BEFORE you are exposed to the hazard, you will not get LUNG DAMAGE.
You are still subject to Environmental Damage. (When the health bar gets a yellow section)
So, walking over a Toxic Gas Vent won't instantly give Lung Damage.
EXCEPTIONS: Attacks that may cause lung damage will still occur: Terromorph, some weapons effects...

Note: These immunities only affect Airborne type hazards, not Thermal, etc.

3) The rate at which a hazard will deplete your suit protection has been cut in half.
A Toxic Gas Vent for example.
The rate was so high before that you rarely even noticed the protection time if you had low resistance.
EXCEPTION: Attack effects like the Terromorph have been unchanged and some hazards like lava don't use this variable.
Note that some extreme environments immediatly deplete your protection, intentionally.*

4) Weather Hazards: Freezing Rain, Freezing Fog, Scalding Rain, Extreme Cold Snow, etc.
The rate at which it depletes your suit protection has been drastically reduced (about 80%).
The amount of time you can spend out in these conditions has been lengthened considerably.
Yes, you have to listen to the beeping as it depletes your suit protection.
You CAN still get an AFFLICTION. Frostbite, Hypothermia, Burns, etc. but it will take longer. 
NOTE: Some extreme environments will instantly deplete your suit protection as soon as you leave your ship so you won't hear any beeping.
See below *

5) All Environmental Resistances have been uncapped. Thermal, Airborne, Corrosive, Radiation
In the vanilla game these resistances were capped at 85% maximum. This mod changes it to 100%
So if you can get a spacesuit, pack and helmet that add up to 100 then it will give 100% resistance to that hazard.
When at 100% Airborne resistance for example you can stand on top of a Toxic Gas Vent and nothing happens.
HOWEVER: These resistances only have influence on the rate of suit protection depletion, then when fully depleted, the rate at which
you receive environmental damage.
These resistances have zero influence on the chance to receive an affliction. That would require changes to the base scripts.
The skill below can help though.

6) The Environmental Conditioning Skill has an added perk.
Previously, only Rank 4 would increase your "Chance to avoid Injury", which means avoiding things like Burns, Frostbite, etc.
Now, each rank increases it slightly. I just listed the magnitude. 2,4,6,8.
(I don't know what metric they use for this. Rank 4 was magnitude 7. 7 Percent? who knows...)
So, a character without this skill has zero chance to avoid injury from an environmental hazard.
No wonder you would instantly get frostbite if you didn't get inside the Red Mile fast enough.


* EXTREME ENVIRONMENTS:
Some planets will have an "Extreme Environment" which will show a warning on the watch face.
Solar Radiation
Cold
Heat
Toxic Atmosphere
Corrosive Atmosphere
An extreme environment will immediately deplete suit protection.
There is only one suit protection "pool". There aren't separate ones for Airborne, Thermal, etc.
So, if one type of hazard depletes the suit protection you will have none left for a different type of hazard.

For example: You land on a planet with Extreme Solar Radiation, which will instantly deplete suit protection when you leave your ship.
You later walk over a gas vent and instantly get environmental damage because your suit protection was already used up by the solar radiation.


Compatibility:
It may conflict with mods that also alter the environmental hazard system. I haven't tested anything.
This mod tends to be the opposite of a survival mod so it might not be a good combination.
No changes to scripts.
This is a small master ESM.