Obviously, this person will face nearly the same issues as someone in the vacuum of space.
There have been several experiments and incidents where portions of (or entire) humans (and even more animals) are exposed to a hard vacuum, which is what you're describing.
The Wikipedia page describes the symptoms for being in space like this:
The key concerns for a human without protective clothing beyond Earth’s atmosphere are the following, listed roughly in the descending order of mortal significance: ebullism, hypoxia, hypocapnia, decompression sickness, extreme temperature variations and cellular mutation and destruction from high energy photons and (sub-atomic) particles.
Your situation is only slightly different in the items of least mortal significance are not a factor. The symptoms of highest mortal significance are still factors.
The formation of gas bubbles inside the fluids of the body. Think about opening a bottle of carbonated beverage, in a less dramatic way, something similar will happen to any exposed fluids in and on your body.
Also known as "I can't breathe!". You're no longer getting oxygen. This is an immediate problem. Everything in your body will be letting you know that you need to do something about this right now.
Less well known, but you can simulate it by hyperventilating. So may be known as "I breathed too much!". This is a reduction of carbon dioxide in your blood. This causes pins and needles, muscle cramps and tetany in the extremities, especially hands and feet.
Ah, the bends. It sounds like an affliction of someone who frequently drops things. In this case you may drop an arterial gas embolism into your brain and you will have a stroke. Which is less a whimsical name for a clumsy person and more of a you need help with the toilet now, if you're lucky.
These symptoms could be worsened depending on the speed at which the pressure drops around the target (and vice versa). But in general it would be an effective way to kill someone in a few minutes. Incidentally your exposed subject will likely feel very warm, as vacuum is an excellent insulator. Additionally they will be flushing as their capillaries and blood vessels near the surface of the skin expand (some small ones may break, but no one is going to explode).
The most important part to remember about vacuum is that vacuum doesn't suck. When there is a low or zero pressure things blow into them. Humans don't explode in space because our bodies aren't an explosion being held in by air pressure. Did you ever wonder how the tires on the space shuttle don't explode in space? It's because moving them from Earth atmosphere to vacuum is equivalent to putting 14.7 psi more air pressure into them, an insignificant amount compared to the 340 psi they're already inflated with.