cosmic rays - Energy of single particles, measured in kelvin?

This page says cosmic photons have an energy of 2.78 kelvin, so how much energy would the particles that show up in a bubble chamber have?

Answer

The cosmic-ray tag wiki already explains this:

Usually referring to stable high energy elementary particles - cosmic rays were found to arrive the Earth from galactic and extragalactic sources and interact with the atmosphere. The energies of this particles are one of their prominent features and extend over multiple orders of magnitude, at least up to $10^{20}eV$.

So going by this table, that's widely about 1.0E20 / 1E9 = 1.0E11 GeV, so 1.0E11 * 1.16E13 = $1.16^{24}K$. Enough to boil 5E-7 liters of 25 degree Celsius water.