Well, I'm wearing a gasmask, and in a sphere of reinforced glass (with a plant, of course).
I pour a mixture of chlorobenzene, petroleum and thermite over the next user's head then burn it.
It turns out that the decay was simply an isomeric transition, which means that I emit a gamma ray, while not losing any nuclear particles. After the transition finished, I had become a stable atom.
The next user is a normal human who has been frozen in liquid helium, and then dumped onto the surface of Pluto.
as it turns out, there are aliens on Pluto, and they see what is going to happen and manage to save me and send me back to earth after getting me out of the ice.
the next user shoots themself in the face.
I'm wearing a titanium bulletproof helmet that protects my face.
The next user is a cell attacked by strong viruses.
However, I am the wrong type of cell for the virus to attack, so I am untouched by it. (Viruses are cell-specific.)
The next user's atoms suddenly undergo spontaneous nuclear fission.
I am wearing a gas mask with an oxygen tank, There is a ship to go to planet Mars, Mars have terraformed in the Year 6477 AD so Mars can be habitatable... Search it here. http://en.wikipedia.org/wiki/Terraforming
The next user is in the center of the Planet Neptune where the pressure is very very very high that can liquefie you into pieces.