If you were suddenly transported to Lagrange point 2, in vast emptiness of space right next to Webb, you wouldn’t die right away. You wouldn’t explode, because your skin is strong enough to withstand the pressure differential between earth and deep space. You wouldn’t instantly freeze either—space is a vacuum, so you’d lose heat slowly.
Instead, you’d have some time out there. Not much, because you wouldn’t be able to breathe, but maybe 15 seconds of consciousness, enough time to really think about your situation before you blacked out and fully died a few minutes later. The very last thing you would experience would be your own saliva boiling in your mouth.
We know this because something like it actually happened in 1966 to astronaut Jim le Blanc. When the spacesuit he was testing in a vacuum chamber sprung a leak, le Blanc was exposed to a full-space vacuum for about 30 seconds. He survived unharmed because they pulled him out quickly, but le Blanc said he felt the spit on his tongue boil before he blacked out. (He also said he had an earache.)
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