Space travel has become more of an interest today than it was during the first moon landings. This might be since many Hollywood movies such as Gravity and Interstellar have made space travel look so exhilarating and exciting that every one of us now wants to go into space. However, the query which most people commonly have is what will happen to us if we do not have our space suit on. Some of us believe the dramatic version of such a situation as it is showcased in movies. The question remains, however, that, do we explode or could we somehow survive.[irp]
Earth provides us with a cozy existence as it blocks out all the harmful UV rays of the sun and maintains a bearable pressure. Space, however, is a complete vacuum which is extremely hostile to our bodies. Our atmosphere is the only thing separating us from the rest of outer space. The most dangerous exposure we get in outer space is the lack of oxygen and ebullism. Ebullism is another word for the process of bubble formation in the fluids of your body, due to the pressure change. The increase in pressure and the decrease in your body temperature will cause gas bubbles, which will cause you to grow to almost double your size, but you would not blow up thanks to our stretchy skin. Your blood will not boil up as it is commonly believed, but you will suffer a great amount of pain and the circulation of your blood is greatly hampered.
After 15 seconds of being exposed to space, your body will run out of all the oxygen which is stored in your body and you would be rendered unconscious. Some people might think that they could beat this time by holding their breath (those who can hold their breath for longer than 15 seconds). This could possibly be a fatal thing you could do, as the atmosphere in the outer space will cause whatever air trapped inside your body to expand which will damage your lungs.
After you become unconscious, you will probably stay alive for a few more minutes. The horrible unfiltered UV rays will give you nasty sunburns. These UV rays also are extremely harmful to your DNA, which would lead to mutations and ultimately cancer. The cold temperatures of space will however not freeze your body, as the vacuum in space will cause heat to move out of your body extremely slowly.[irp]
The purpose of this was to answer the most common query, that instead of blowing up, you will burn, mutate, swell up, pass out and there is a high probability that your lungs will explode. However, there is no need to worry. If you somehow get trapped in such a situation (which is highly unlikely), you will have around 2 minutes or less to be rescued, so hope for the best.