Objectives: The aim of this study is to investigate the influence of post-traumatic stress disorder (PTSD), peritraumatic dissociation, psychological distress and subjective health complaints in the psychological well-being of the emergency ambulance personnel. Methods: This is a cross-sectional study in which 250 ambulance personnel; both sexes completed a self-administered questionnaire, with measures of post-traumatic stress disorder, peritraumatic dissociation, psychological distress, subjective health complaints, psychological well-being and socio-demographic variables. Results: The results indicated that ambulance personnel have on average some PTSD symptoms, while 10% have a clinical diagnosis of PTSD, peritraumatic symptoms are also significant, as well as psychological distress and health complaints. Correlational analyses indicated a negative significant association between symptoms and psychological well-being. The peritraumatic dissociation, the subjective health complaints, psychological distress and sex were found to be predictors of the post-traumatic stress disorder. There were significant differences concerning the socio-demographic variables in relation to the dependent variables. Implications: The results of this study highlight relevant indicators of the need to develop and implement intervention programs to alleviate the psychological suffering, promoting the adjustment and the physical and psychological well-being in emergency ambulance personnel. Conclusions: This study presents a contribution to understanding the psychological consequences of daily exposure to traumatic incidents, and its impact on health and well-being of emergency ambulance personnel. Background: Nepal has different climate zones from ice freeze cold to hot in plain tarai regions. The maximum temperature is around 45-52o C. Implicit in all indices used for risk assessment in the prevention of heat stress is the assumption that workers are healthy and well hydrated; studies in Nepal cement, iron factory workers where workers are poorly hydrated, the level of protection offered by management strategies based primarily on environmental monitoring is compromised. Objectives: To investigate the hydration status of expatriate workers during summer in a range of works as large numbers of expatriate workers are employed as manual labourers in industries under extreme heat stress conditions where heat illness is a significant concern. The aim was to ascertain whether the generally inadequate hydration status, is also an issue in these workers and make practical recommendations for control. Methods: Studies were carried out at four sites to document the hydration status of exposed workers in different workplaces using urine specific gravity at three time points over two different work shifts. Results: Although the workers were found in general to be better hydrated than their other zone counterparts, a high proportion were still found to be inadequately hydrated both on presentation for work and throughout the shift. Workers take less drinking water and more alcohol, smoking. Conclusions: Interventions are required to ensure that workers in extreme heat stress conditions maintain adequate levels of hydration. Behavior change among workers to drink plenty of water, fluids and avoid alcohol, smoking, adequate sleep and rest. Failure to do so reduces the protection afforded by heat stress indices based on environmental monitoring. Regular Health assessment and behavior change programs in those areas is important for safety and reduce occupation health hazards as well. (2010) 17 (Suppl 1):S1-S329 S135