The purpose of this study is to assess sleep and wake parameters in veterans of the first Gulf War who have fatigue and other symptoms compared with veterans who do not have fatigue utilizing novel assessment techniques including high density EEG and temperature. This research study is in the data collection and data processing phase. The most significant findings to date in this study during the research period include continued evidence of high density EEG marked broad band reduction in neural activity circumscribed in the frontal cortex in NREM sleep. Slow wave sleep is considered to play a role in the recovery and restorative aspects of sleep, and is one bandwidth affected. In addition, melatonin curves, particularly dim light melatonin onset, which is well-tied with circadian sleepwake and subsequent feelings of fatiguealertness show different projections in veterans endorsing fatigue than those who do not.