In the Star Trek universe
By this I`m saying, too many Class Ms, virtually 99% of landing parties did so minus Space or Environmental Suits to protect them.
Off the top of my head I can only recall suits being worn in The Naked Time and The Tholian Web (no doubt someone will correct me), and it got me thinking that some situations could have been more interesting with oxygen supplies, or lack of them, as a hindrance.
They did have those mask things, briefly, in The Squire of Gothos I believe.
Just a thought for your discussion.