Atmospheric-pressure helium discharges have been developed extensively in the last two decades for various biomedical applications such as wound healing, cancer treatment, and sterilization due to the efficient generation of reactive species. Discharge temperature is one of the major concerns for applications with discharge treating human tissues. This project will conduct thermal analysis for atmospheric-pressure microsecond pulsed helium discharges including experimental measurements and numerical simulations. The temperature distribution of the reactor surface will be measured via the rotational spectra (i.e., N2(C->B)) collected by the spectrometer. A computational fluid dynamic (CFD) model will be built with the heating source evaluated by the plasma fluid model to simulate the temperature distribution within the reactor. The simulated results will be validated and the plasma heating mechanisms will be studied.