A G-Suit, or the more accurately named anti-g suit, is a flight suit worn by aviators and astronauts who are subject to high levels of acceleration force (g). They are designed to prevent a black-out and g-LOC (g-induced loss of consciousness) caused by the blood pooling in the lower part of the body when under acceleration, thus depriving the brain of blood
Where as, with their thin material and their network of tubes, these suits actually looked more like they might be used solely for the purpose of cooling the wearer. I spent a bit of time searching for clues but failed to make inroads. So I did what I always do when I need help with a post, I ask for it. And that's where a blogger from Newtonphotographic.com stepped in to say those magic words;
They're actually 50s vintage Royal Air Force Air Ventilated Suits - as seen here about 2/3rd of the way down the page
They were worn under flying suits in hot climates and the tubes are for cold air to be blown through them from the aircraft A/C system.
Well what do you know, I found this...
and a whole lot of history. That's just a teaser section of a larger picture but as its not mine to show I'll let you follow the link and find it with your own eyes.
Anyway, once you know the name of what your looking for it suddenly gets a whole lot more interesting and fruitful.
and although it has long since sold, they too describe it thus...
a vintage 1950's RAF issue air ventilation suit. It is made of parachute material and has all kinds of hoses attached to it. It would make a great Halloween costume for somebody. These were made to be skin tight so this would probably be most suitable for someone around 5'7" or so who is quite slim. Then it would not be so tight. It is not in perfect condition since these is a rip along the edge of the slit at the back
And provided further images
and from the comments section of that website, these little snippets;
The air ventilated suits were worn inside pressure suits used by air crew flying at high altitude.
Often nicknamed the ‘Fairy’ suit, the air-ventilated suit was produced to give relief from discomfort of high cockpit temperatures by moving cool air to the wearer’s skin via some 144 PVC tubes, with one larger ‘inlet’ tube.
Now you just know the ethereal Kate Bush would have been delighted to know the ventilation suits by that particular name.