Recently several proposals have been made to utilise heavy ion collisions at the LHC to search for New Physics. While the luminosity and centre-of-mass collision energy in heavy ion collisions are lower than in proton collisions, they offer a number of unique advantages. On one hand this includes new production mechanisms that are absent or suppressed in proton collisions, but allowed in heavy ion collisions, either due to the presence of the quark-gluon plasma or by the extremely strong electromagnetic fields that are generated in a fly-by of ions. On the other hand one can take advantage of the different backgrounds in heavy ion collisions, such as the absence of pile-up and the possibility to operate the main detectors with looser triggers. After a general overview of some of the ideas discussed in the literature I focus on our own proposal to search for new long lived particles in heavy ion collisions.