Retired NASA astronaut Chris Hadfield states that an individual can survive in space for about 30 seconds without a spacesuit! The movie Guardian of the Galaxy 3 shows Star-Lord AKA Peter, in space where his face starts to freeze before it starts swelling up!
According to Hadfield, if a person stays in space without a spacesuit, it will do irreversible damage, leading to death due to the lack of oxygen. The blood in the body will lose all its oxygen. Thus, the brain will experience a lack of oxygen, doing irreparable damage to the body and the brain.
Even though the scene in Guardians of the Galaxy 3 is quite emotional and realistic with the visual perception of things. However, scientifically explaining that is different from what happens! Once a person is left unprotected in space for more than 1 minute 30 seconds, there is no way they can return from it!
The real-life NASA scientist Hadfield informs that it is not scientifically accurate to bring back a person to life once they die in space! However, it is the movies, and ofcourse, the storyline can be bendable, and it does not need to be scientifically accurate!
Adam Warlock finally saves the character of Star-Lord. Before that, all the film's characters watch Star-Lord slowly slipping into oblivion! The time through which Star-Lord suffers in space is more than 90 seconds.
In an interview with Vanity Fair, Chris Hadfield, a retired engineer and astronaut for NASA, informs that no one can survive more than a minute and 30 seconds in space without a spacesuit!The astronaut also says, “90 seconds and you’re a satellite!” This might sound funny, but it is a serious matter, especially if it is happening in real life! He says a person cannot pop their helmet off and travel in space, there is a reason for the spacesuit!