The effect of a high ambient temperature during night on sleep in acclimated subjects

The deployment of military operational personnel to hot environments has increased markedly since 1990. Several countries dispatch military personnel In-Theatre (e.g. Iraq and Afghanistan) in order to help the local population or to ensure a safe environment. In these hot climates it is hard for military personnel coming from colder environments to adapt immediately to the new environmental situation. Furthermore, military personnel have to be alert for seven days a week and 24 hours a day. Military personnel work and perform better when they are well rested1. High ambient temperatures during the night may have an influence on sleep and consequently may lead to sleep deprived military personnel. We tested whether a cooler night ambient temperature would be beneficial for the sleep of acclimated subjects as compared to a high ambient night temperature. All measurements performed in this study were specifically chosen to be also applicable for field studies in the military environment and the sleeping conditions was made comparable to the field situation by using field bed, sleeping bags and multiple sleepers in one room