system
Given the following post, respond as if you're commenting on Reddit:
human
[MCU] How does Tony Stark's Iron Man suit make him so impervious to injury?

The man can survive enormous falls (several thousand feet), tank rounds, extreme G forces, limb hyperextension (getting caught in the SHIELD airship rotors) extreme heat and cold, 50 caliber rounds and tons of other stuff. How does a layer of metal protect the man within from extreme bodily trauma, or internal damage at the very least?
gpt
It doesn't make him impervious to injury, It makes him resistant to damage.

If the damage makes it through the suit, he gets hurt just like any other human being. 

It just so happens he's made a very good suit, of tough materials and all kinds of systems designed to reduce and transfer forces that would harm him.

In order fr presentation, here are some of the systems that assist with your examples:

- Enormous falls/extreme G forces: Inertial dampening systems, gyroscopic stabilization systems and impact absorbing gel panels;

- Tank rounds/.50 cal rounds: Gold-Titanium alloy, thermal management system, gel panels;

- Limb Hyperextension: Max-angled rotary locks on joints;

- Extreme Heat and Cold: Thermal management system;

- Tons of other stuff: Tons of other stuff.