There is a shortage of evidence regarding the stability and safe use of normal saline stored under stressful conditions within ambulances. Our objective was to evaluate how exposure to extreme temperature fluctuations affects the stability of normal saline and its compatibility with the packaging materials. Ninety-six polyolefin bags of normal saline were exposed to constant temperatures of 22, 50, or 70 °C, or to cycles of 70 °C for 8 hours and 22 °C for 16 hours. Bags were sampled at set intervals—up to 72 hours for the short-term study and weekly for four weeks in the long-term study. Solutions were inspected for crystallization, discoloration, turbidity, and pH changes, and samples were analyzed for sodium and chloride content. No precipitation, discoloration, or turbidity was observed in any of the normal saline bags. The mean pH values measured were 5.59 at 22 °C, 5.73 at 50 °C, 5.86 at 70 °C, and 5.79 under cyclic temperature conditions. Across both short- and long-term studies, sodium concentrations ranged from 100.2% to 111.27%, while chloride levels remained between 99.04% and 110.95%. No evidence of plastic component leaching from the polyolefin containers into the saline solution was detected. Sodium and chloride concentrations in normal saline remained stable and showed compatibility with polyolefin bags after exposure to simulated continuous and cyclic extreme temperatures for approximately one month. However, the influence of storage within ambulance cabinets across different seasons in arid regions still requires real-world investigation to validate these findings.
