The thermal conductivity is a fundamental property of plasmas, yet its experimentally observed reduction remains an enigmatic phenomenon. Over the past half-century, extensive efforts have been dedicated to elucidating the mechanisms behind this reduced thermal conductivity and the associated heat-flux limiter, but a definitive solution has remained elusive. In this work, we present an analytical model for plasma thermal conductivity that is free of artificial parameters. This model employs Maxwell distributions for both electrons and ions and provides analytical expressions for thermal conductivity and the heat-flux limiter. Importantly, the predictions of the model are in good agreement with experimental observations. Its validity extends across plasmas with both small and large temperature gradients, significantly enhancing its applicability. This straightforward model not only offers insights into the underlying physics of reduced thermal conductivity and the heat-flux limiter but also plays a crucial role in advancing our understanding of thermal transport in plasmas across diverse areas.