No more cold airlessness

[Remmon]

Or well, https://www.youtube.com/watch?v=ejlKsj7k4Rc

There are a few slight problems with that demonstration.

1) The vapour pressure of blood is much higher than that of water. In a vacuum the water would slowly boil out of the blood, but the process would be very slow.

2) The mechanical counter pressure that the human body is capable of producing exceeds said vapour pressure, blood will not boil inside your body even in a vacuum. You will get the bends from nitrogen and oxygen coming out of solution but with quick treatment and short exposure times, that isn't necessarily that dangerous.

3) Since there is no boiling, there is evaporative cooling of the body on the large scale. Only small amounts of liquid are evaporating off the body. This is why mechanical counter pressure suits work, they can augment the body's own capability to keep the interior internal to the point where you can breathe and avoid the bends. To reduce the problem of overheating, these suits are typically not moisture tight and as such cause dehydration. In real life this is a process of hours and can be easily slowed down sufficiently by just drinking enough water.

If you want a different method for vacuum damage without making it a huge problem, my suggestion would be for uniforms to be MCP suits and dehydration to be made unnaturally fast. With internals but without a proper helmet, you would start to suffer eye damage after a short exposure to space and take minor brute damage. Over a period of minutes you would start to get dehydrated and need to either drink a bunch of water (Obviously while in normal atmosphere, drinking water in space should give frostburn) or get an IV.

Without a uniform, you would be unable to breathe (even with internals), start to suffer brute damage immediately and get the bends.

If you want space to be a little more dangerous, make the uniforms only suitable for much lower pressures. They'll still allow you to breathe and stop the worst of it, but you would get the bends and eye damage would still be a problem without a helmet.