You wouldn't notice it. The energy is sufficient, but the momentum is too small. Energy goes up with square of velocity and momentum just linearly, so this part

You wouldn't notice it. The energy is sufficient, but the momentum is too small. Energy goes up with square of velocity and momentum just linearly, so this particle gets more of its energy from velocity and less from mass compared to a macroscopic object. The result is lowish momentum. It probably hits a water molecule and the heat is quickly dissipated. You don't recoil because the momentum is small. It might kill a few cells, but far smaller than the ordinary cycle of life. So any effect is swamped.