1. A person does not become instantly piece of ice?
Heating or cooling occurs either due to contact with a cold environment, or through radiant heat.
In a vacuum environment no, not in contact with anything. And to be precise, in a vacuum there is a very rarefied gas, which due to its discharge of gives a very weak effect. In thermos vacuum is used just to keep warm! Having no contact with the cold matter, the hero does not feel the searing cold.
2. Freezing have long
With regard to radiation, the human body hitting the vacuum will slowly dissipate heat by radiation. The thermos flask make wall mirror to keep radiation. This process is quite slow. Even if there is no astronaut suit, but there are clothes, it will help keep warm.
3. Saute?
But you can get a tan. If it happens in space close to the stars, you can get a sunburn on exposed skin - both from excessive tanning on the beach. If it happens anywhere on the Earth's orbit, the effect will be stronger than on the beach, as there is no atmosphere, which protects against hard UV light. 10 seconds is sufficient to produce a burn. Yet this is not a burning fever, besides clothes, too, must protect. And if we are talking about a hole or crack in a spacesuit helmet, then on this subject you should not worry.
4. Boiling saliva
Boiling of liquids depends on the pressure. The lower the pressure, the lower the boiling point. Therefore, the liquid will evaporate vacuo. It was found in experiments - not once, but the saliva begins to boil as the pressure is almost zero, and the temperature of language - 36 S. Apparently, the same thing will happen with all the mucous membranes (eyes, lungs) - they will dry up unless the the body will not do a new slime.
By the way, if you take not just a liquid film, and a large amount of water, then, perhaps, will be the effect as in "dry ice" outside to evaporation, with evaporation heat is rapidly lost, at the expense of the inside of the freeze. It can be assumed that the water ball partly evaporate in space, but otherwise become a piece of ice.
5. The blood boil?
Stretch the skin, blood vessels, the heart will create enough pressure to no boiling.
6. Effect of champagne is also not expected
In divers have such trouble, as the bends. The reason - something that happens with a bottle of champagne.
In addition there are boiling the dissolved gases in the blood. When the pressure drops, the gases turn into bubbles. The champagne comes dissolved carbon dioxide, while the divers - nitrogen.
However, this effect occurs at high differential pressure - at least several atmospheres. And if it enters the vacuum drop only one atmosphere. The article on this subject says nothing, no symptoms are described - apparently this is not enough.
7. The air inside the break?
It is assumed that the victim of his exhale - and therefore did not break. And if you do not exhale? Assess the threat. Let maintained in a spacesuit pressure of 1 atm. This 10 kg per square centimeter. If a person tries to hold his breath, the air gets in the way of the soft palate. If there is an area at least 2x2 cm, then get a load of 40 kg. It is unlikely that the soft palate survive - people exhale myself blown away like a ball.
8. The person suffocates?
That is the major and real threat. I have nothing to breathe. How many people can survive without air? Trained divers - a few minutes, untrained people - no more than a minute.
But! It's a breath when the lungs full of air with the remnants of oxygen. And then, remember, have to breathe. How many people can hold a simple exhale? But 30 seconds! On the exhale, the lungs are not "skukozhivayutsya" until the end, there is little oxygen. In space, apparently, will be even less oxygen (how many will be able to keep). The exact time in which the person loses consciousness from asphyxiation known - about 14 seconds.
But 10 seconds a person in a vacuum still exists!