Gell-Mann - Oakes - Renner relation in a magnetic field at finite temperature

In the first order of chiral perturbation theory the corrections to $F_{{\pi }^0}$ and $M_{{\pi }^0}$ in a magnetic field at finite temperature have been found. It was shown that they are shifted in such a manner that Gell-Mann - Oakes - Renner relation remains valid under these conditions.