Elucidating the nature of magnetism in a high temperature superconductor is important. Our previous neutron measurements at low temperature revealed a resonance mode at Q = (pi, 0.62*pi) in heavily electron doped FeSe superconductor Li0.8Fe0.2ODFeSe (Tc = 41 K), which is different from that in FeAs superconductors. Most notably, we show that the spin excitations disperse outward at low energies and then inward at higher energies which is quite unique as well. These results suggest that the spin excitations might have different origins here which will lead to different temperature dependence. Very recently, our neutron scattering experiment on a triple axis spectrometer showed that the low energy spin excitation dispersion is indeed highly temperature dependent. Here we propose to measure the temperature dependence of high energy spin excitations from 50 K to 300 K in Li0.8Fe0.2ODFeSe.