In this research, thermal displacement and stress fields in an initially stress-free hollow nanosphere due to constant temperature changes are analyzed according to linear theory of thermoelasticity. Surface effects are considered because of large surface-to-volume ratio in nanoscales. Closed form solutions are derived and results are demonstrated with numerical examples to examine the effects of size and surface energy. It is shown that thermal displacement and stress components are extremely size dependent and are effectively influenced by surface energy. This study might be helpful for the design and control of MEMS, NEMS and nanodevices