The impact of temperature and storage time on military packaged water (MPW) quality was examined at four temperatures (23.0. °C to 60.0. °C) for 120. days. Polyethylene terephthalate (PET) bottles were filled in California and Afghanistan with unbuffered water treated by reverse osmosis. The US military's water pH long-term potability standard was exceeded, and US Food and Drug Administration (USFDA) and US Environmental Protection Agency (USEPA) drinking water pH and odor intensity limits were also exceeded. During a 70. day exposure period, Port Hueneme MPW total organic carbon and total trihalomethane levels increased from <. 0.25. mg/L to 2.0. ±. 0.0. mg/L and <. 0.05. μg/L to 51.5. ±. 2.1. μg/L, respectively. PET released organic contaminants into MPW and residual disinfectant generated trihalomethane contaminants. After 14. days at 37.7. °C and 60.0. °C, Afghanistan MPW threshold odor number values were 8.0 and 8.6, respectively. Total organic carbon concentration only increased with exposure duration at 60.0. °C. Acetaldehyde and formaldehyde contaminants were not detected likely due to the high method detection limits applied in this study. Phthalate contaminants detected and their maximum levels were butylbenzylphthalate (BBP) 0.43. μg/L, di-. n-butylphthalate (D. nBP) 0.38. μg/L, di(2-ethylhexyl)phthalate (DEHP) 0.6. μg/L, and diethylphthalate (DEP) 0.32. μg/L. Antimony was only detected in 60.0. °C Afghanistan MPW on Day 28 and beyond, and its maximum concentration was 3.6. ±. 0.3. μg/L. No antimony was found in bottles exposed to lesser temperatures. Environmental health, PET synthesis and bottle manufacturers, and bottle users can integrate results of this work to improve health protective decisions and doctrine.