In this talk, I present the current lattice study of the thermal
transition of QCD by means of twisted mass Wilson fermions by the tmfT
collaboration. This particular lattice discretisation provides an
automatic improvement in the leading order of lattice artefacts if the
original untwisted mass parameter is tuned appropriately to achieve
so-called maximal twist.
I discuss properties of twisted mass fermions at finite temperature in the
weak coupling limit as well as the non-trivial phase structure in bare
parameter space. Particularly the latter is very important to know in
order to find suitable parameter ranges for simulations aiming at the
physical transition. Finally, I present our on-going work which is is
devoted to the thermal transition in the two-flavour chiral ĺimit.