  Infrared singularities in massless gauge theories are known since the
foundation of quantum field theories. The root of this problem can be tracked
back to the very definition of these long-range interacting theories such as
QED. It can be shown that singularities are caused by the massless degrees of
freedom (i.e. the photons in the case of QED). In the Bloch-Nordsieck model the
absence of the infrared catastrophe can be shown exactly by the complete
summation of the radiative corrections. In this paper we will give the idea of
the derivation of the Bloch-Nordsieck propagator, that describes the infrared
structure of the electron propagation, at zero and finite temperatures. Some
ideas of the possible applications are also mentioned.
