Natural and prescribed fires play an important role in managing and maintaining most ecosystems in the western United States. The high soil temperatures associated with fire influence forests and their ability to regenerate after a fire by altering soil properties and soil chemistry and by killing microbes, plant roots, and seeds. Because prescribed fire is frequently used to reduce surface fuels, it is important to know how fuel conditions, soil moisture, and soil properties interact to determine the soil temperatures, the depth of the soil thermal pulse, and the response of the soil biota to soil heating. This report presents the results of experimental tests of a high temperature soil heat flux plate and a high temperature soil moisture probe. These sensors are intended to provide data before, during, and after a prescribed burn in support of long term studies of soil microbial response to fires.