ObjectiveTo observe the changes of motion sickness incidences under normal temperature (NT), high environmental temperature(HT), and high environmental temperature/humidity (HTHH), so as to study the influence of high environmental temperature/humidity on the onset of motion sickness. MethodsA total of 459 male students in a university, aged 18-23 years and with normal physical condition/ability, were subjected for Coriolis acceleration test under the condition of 20℃/55%RH (NT), 38℃/55%RH (HT), and 38℃/80%RH (HTHH); then the motion sickness severity was evaluated using Graybiel scale. ResultsThe motion sickness incidences of NT, HT, and HTHH groups were 47.93%, 68.94%, and 100%, and Graybiel scores were (2.07±3.12), (6.06±5.45) and (11.87±3.42), respectively, with the latter significantly higher than those of the former two for Graybiel scores (P＜0.000 1). The severity scales of motion sickness were also significantly different between the three groups (P＜0.000 1).ConclusionHigh environmental temperature and humidity can accelerate the onset of motion sickness and aggravate the symptoms of motion sickness.