The pressure is still 1/3 of an atmosphere approx, regardless of mechanical or gas. The more salient question, to ask those who have experienced it, how do those parts of the body respond to less than normal atmosphere pressure. Sounds like that could be a 'sensitive topic' as well.
Mount Everest is at 29000 feet, where the air pressure is 32 kPa [1], which is about a third of sea level's 101.325 kPa. People have climbed everest without supplemental oxygen, let alone a pressurized suit. I imagine that the body would be fine.
I imagine the body would survive; but 'just fine' may be a stretch. Nobody climbs Everest without damage to their body. Its very harsh.
The human body manages fine with many times atmospheric pressure when diving, so a third less shouldn't really be much of an issue, though I would imagine that the oxygen levels would have to be kept very high at those sort of pressures. And is only the gas in the body that you really need to worry about, the liquids and solids aren't going anywhere.
> And is only the gas in the body that you really need to worry about
The only gas to worry about, aside from carbon dioxide.
'Is only the gas', not, 'is the only gas'. Was talking about all gases, not specifically oxygen.