PIONS may be produced in thermonuclear interactions between nucleons in material at a temperature ≳1010 K. Pion production followed by secondary interaction is among the many processes contributing to the statistical equilibrium of a high temperature astrophysical system. Charged pions do, however, undergo decay as an alternative to secondary interaction, producing μ-neutrinos (vμ); if these neutrinos have a high escape probability, their emission may cause an appreciable energy loss from the system.