Practical understanding of energies in LHC collisions Is visible light emitted at the point of collision in the LHC? If so, how bright?  How much water could be heated up by 10 degrees celsius (this is the energy from collision only, not the energy to accelerate/guide the particles).
 A: The current collision energy of the restarted, upgraded LHC is 13 TeV. This is about $2 \times 10^{-6}$ Joules. Water has a specific heat capacity of about 4.2 Joules per gram per degree Kelvin. So this tiny amount of energy would heat up a gram of water (i.e. a large drop) by about $5 \times 10^{-7}$ degrees.
That's for a single collision between two protons. 
However, the beams contain of the order of $10^{14}$ protons so the beam energy is actually a sizeable 360 Megajoules. That is enough energy to heat water by about $10^{5}$ kg-degrees. That is, it would heat 1000 kg of water by 100 degrees - so you could boil a large bath.
This page has some other examples about what you can do with the energy.
A: Since all that 360MJ is concentrated in a beam of 2800 segments each about 30cm in length and 1mm diameter and it's total equivalent energy is about that of 77kg of TNT, if you got hit with it there would not be much left. The beam would dump its energy in about 100uS, resulting in a power of about 3.6 petaWatts
