Immediate exposure to a vacuum can lead to serious physiological effects, including potential lung damage and nitrogen bubbles forming in the blood, similar to decompression sickness experienced by divers. Contrary to popular belief, a human does not explode in a vacuum; instead, blood may escape the body, and consciousness can be maintained for about 10 seconds, with possible survival for up to 90 seconds. The discussion references the accuracy of depictions in films like "2001: A Space Odyssey," noting that the sequence involving vacuum exposure was timed accurately. It is emphasized that while explosive decompression can cause ear and lung damage, the body has a limited time before severe effects like boiling blood occur. Understanding these effects is crucial for both safety in space exploration and accurate portrayals in media.