@stonemetal has the right answer.

Additional points of interest:

1. Holding your breath is likely to damage your lungs so exhale forcefully while you break wind
2. Because the partial pressure of oxygen in your blood is above that of the pressure of space (aka 0), oxygen will boil out of your blood rapidly causing anoxia (thus the short time to unconsciousness)
3. Exposed skin will likely bruise - so if you have no protection, you'll end up with a whole body bruise.
4. In general, freezing/cold is not an issue. However, moist surfaces could experience freezing from the flash evaporation of water (e.g. eyeballs & mucus membranes)
5. As mentioned above, without prebreathing the victim will suffer from decompression sickness (the bends)
6. Exposed skin could suffer from photon radiation (really bad sunburn) depending upon your location (e.g. in or out of shadow)
7. If 15 sec of consciousness in vacuum corresponds to 60 seconds of consciousness at STP; then we can estimate brain damage from anoxia begins in 1-2 minutes and death is nearly certain after 5 minutes.
8. Oh, and it ought to feel worse than the worst hicky you can imagine over your entire body - including your lungs.

@stonemetal has the right answer.

Additional points of interest:

1. Holding your breath is likely to damage your lungs so exhale forcefully while you break wind
2. Because the partial pressure of oxygen in your blood is above that of the pressure of space (aka 0), oxygen will boil out of your blood rapidly causing anoxia (thus the short time to unconsciousness)
3. Exposed skin will likely bruise - so if you have no protection, you'll end up with a whole body bruise.
4. In general, freezing/cold is not an issue. However, moist surfaces could experience freezing from the flash evaporation of water (e.g. eyeballs & mucus membranes)
5. As mentioned above, without prebreathing the victim will suffer from decompression sickness (the bends)
6. Exposed skin could suffer from photon radiation (really bad sunburn) depending upon your location (e.g. in or out of shadow)
7. If 15 sec of consciousness in vacuum corresponds to 60 seconds of consciousness at STP; then we can estimate brain damage from anoxia begins in 1 minute, death is likely to occur in 1.5 - 2.5 minutes, and death is nearly certain after 5 minutes.
8. Oh, and it ought to feel worse than the worst hicky you can imagine over your entire body - including your lungs.