  We study the effect of temperature on beta decay rate during primordial
nucleosynthesis. Using thermal contributions to the renormalized mass of
electron, we re-compute thermal effects to the nucleosynthesis parameters in
the early universe in relation to the thermal self-mass of electron. In this
study we show how the presence of fermions in a medium cause the variation in
nucleosynthesis parameters with temperature. Before and after nucleosynthesis,
temperature contribution from the electron self-mass goes away. The temperature
dependence of beta decay rate, helium abundance and energy density of the
universe are calculated as a function of temperature during nucleosynthesis.
The values of these nucleosynthesis parameters before and after the
nucleosynthesis are also calculated.
