Purpose: For the treat hypothermia patients, active warming might be needed. In most emergency departments, IV warm saline infusion is used for treatments. However, during IV warm saline infusion, heat loss from the warm saline may occur and aggravate hypothermia. Thus, in this study, we conducted an experiment on conserving heat loss from warm saline by using a simple method. Methods: Four insulation methods were used for this study. 1) wrapping the set tube for the administration of the IV fluid with a cotton bandage, 2) wrapping the set tube for the administration of the IV fluid with a cotton bandage with aluminum foil, 3) wrapping the warm saline bag and tube with a cotton bandage, and 4) wrapping the warm saline bag and tube with a cotton bandage with aluminum foil. Intravenous fluid was preheated to a temperature between $38-40^{circ}C$. The temperatures of the saline bag temperature and the distal end of the IV administration set were measured every ten minutes for an hour. The infusion rate was 1000 cc/hr, and to obtain an accurate infusion rate, we used an infusion pump. Results: The mean initial temperature of the saline bag was $39.11^{circ}C$. An hour later, the fluid temperature at the distal end of the fluid temperature ranged from $39.11^{circ}C$ to $34.3^{circ}C$. Without any insulation, the initial temperature of the pre-heated warm saline, $39^{circ}$ had decreased to $34.8^{circ}C$ after having been run through the 170-cm-long IV administration tube, and after 1-hour, the temperature was $29.63^{circ}C$. As we expected, heat loss was prevented most by wrapping both the saline bag and the IV administration set with a cotton bandage and aluminum foil. Conclusion: Wrapping both the saline bag and the IV administration set with a cotton bandage and aluminum foil can prevent heat loss during IV infusion in Emergency departments.