Fig. 3.

Postoperative temperature on return to the NICU across sequential hypothermia prevention phases. An individual chart displaying postoperative axillary temperature on return to the NICU for 39 sequential surgical cases. Solid horizontal lines represent phase-specific mean temperatures. Dashed lines indicate upper and lower control limits, calculated separately within each phase, based on point-to-point variability using the moving-range method. The shaded band indicates the clinical normothermia target range (36.5–37.5°C). Vertical dotted lines mark transitions between the baseline period and successive intervention phases. Phase-specific estimates should be interpreted with caution due to the limited number of observations in some phases.