  This paper discusses relativistic corrections to the thermal Coulomb
potential for simple atomic systems. The theoretical description of the
revealed thermal corrections is carried out within the framework of
relativistic quantum electrodymamics (QED). As a result, thermal corrections to
the fine and hyperfine strucutres of atomic levels are introduced. The theory
presented in this paper is based on the assumption that the atom is placed in a
thermal environment created by the blackbody radiation (BBR). The numerical
results allow us to expect hteir significance for modern experiments and
testing the fundamental interactions.
