At the high speeds The Flash travels at, he must be generating vast amounts of friction from the air around him.
What is his suit made out of, that prevents it from instantly bursting into flames?
None of his/their suits had any particular property that protected them from destruction. The protection came from the Flash's speed-force generated aura.
The Flash's body is surrounded by what he calls his "speed force aura". This aura protects him and anyone who is running with him or carried by him, from the effects of using his speed. This includes friction and airborne particulate matter.
It also protects him from injury from high speed impacts such as punches he delivers and receives from his opponents. With this aura, he is able to absorb kinetic energy. He possesses a level of superhuman resistance to injury which at times does extend far past normal physical interactions, as received from normal combat.
- Barry designed a special costume. He used a special cold cast polyester he developed in college, which could be molded into miniature outfits from liquid material, that, when submersed in a special liquid, became sensitive to hydrogen, expanding on contact with the hydrogen in the air. A charge from a battery-powered ring he wore on his finger caused the fabric to release the extra hydrogen and shrink into the ring. He later revised the process, making the fabric sensitive to nitrogen instead. ~Flash Vol. 1 #128
The new Flash appears to have taken a step backward and gone back to an armored costume he "transforms" into apparently at superspeed. This costume, like so many in the new DCNU appears as a form of armor.
Barry Allen (played by John Wesley Shipp) was significantly powered down for the Flash's television debut. While he was capable of superhuman speeds, he was without the full capacity of his Speed Force aura.
- When police scientist Barry Allen is struck by lightning and doused with chemicals he discovers that he has become the fastest man alive able to move at nearly the speed of sound. One of the more exciting and atmospheric TV adaptations of a popular comic book series, The Flash benefited from terrific special effects, but lasted only a single year on its network in 1990.
He could breath while running at superhuman speeds but was a bit more vulnerable to kinetic energy and debris while using his superpowers.
Scientist Tina McGee creates a "modified deep-sea pressure suit" which somehow gave him the capacity to survive the use of his powers and his superspeed. It's never explained how he got into it and out of it so quickly. Or where he put it when he wasn't wearing it. I always considered Barry just might have it on under his clothing but that didn't make a lot of sense either.
Curiously enough, the suit did not have goggles or any other eye protection which struck me a bit strange since his eyes would be the most vulnerable part of his body he would definitely want to protect from flying debris at 200+ miles per hour. Oh well, it's just TV. It doesn't always have to make sense.
Actually the 90's show suit was a thick latex that was given a fabric overlay to appear cloth-like. The producers didn't want to have another "batman" looking suit on their hands. Shipp wore a water-cooled suit to combat the tremendous amounts of heat being worn constantly. There were 4 suits made adding up to $100,000 total cost in production.
If you listen to when Cisco gives flash the suit, he says it is a lightweight new suit firemen use with reinforced tripolymer, which is commonly used as strong sealant. CLICK HERE TO WATCH CISCO GIVE FLASH THE SUITresearch on what tripolymer is So if you look, you only have to see what keeps firemen from burning up. A firefighters suit is made of a substance called Nomex, which would keep friction from burning you up,FIREFIGHTER SUIT SUBSTANCE but in order to be able to go that fast, remember, he needs to use reinforced tripolymer for his high speeds. This took me a lot of research but now we can make an EXACT copy.