There are lots of related questions on this site but I couldn't find one that answered your question exactly. If you're interested try searching the site for boiling vacuum or something similar.

The boiling point of a fluid depends on the external pressure. Specifically a fluid will boil when its vapour pressure is greater than or equal to the external pressure. The vapour pressure of water at body temperature is about 0.06 atmospheres, so when the external pressure has fallen below 0.06 atmospheres the water in your body will start to boil.

However as water boils it cools, because heat is carried off by the water vapour. So the boiling will cool your blood/saliva/whatever. The vapour pressure of water is temperature dependant so the cooling will reduce the rate of boiling, and of course at some point it will be cooled enough to freeze. There is some debate about how fast you would freeze because we've never done the experiment. There is some discussion of this in Direct exposure to the vacuum of space and How does space affect the human body (no space suit, no space craft).

Note that ice sublimes in a vacuum so even after freezing you would slowly lose water and dry out. However the rate of water loss gets very low at low temperatures, which is why it's possible ice can be found on the Moon.

There are lots of related questions on this site but I couldn't find one that answered your question exactly. If you're interested try searching the site for boiling vacuum or something similar.

The boiling point of a fluid depends on the external pressure. Specifically a fluid will boil when its vapour pressure is greater than or equal to the external pressure. The vapour pressure of water at body temperature is about 0.06 atmospheres, so when the external pressure has fallen below 0.06 atmospheres the water in your body will start to boil.

However as water boils it cools, because heat is carried off by the water vapour. So the boiling will cool your blood/saliva/whatever. The vapour pressure of water is temperature dependant so the cooling will reduce the rate of boiling, and of course at some point it will be cooled enough to freeze. There is some debate about how fast you would freeze because we've never done the experiment. There is some discussion of this in Direct exposure to the vacuum of space and How does space affect the human body (no space suit, no space craft).

Note that ice sublimes in a vacuum so even after freezing you would slowly lose water and dry out. However the rate of water loss gets very low at low temperatures, which is why it's possible ice can be found on the Moon.