AbstractObjectives: To evaluate the thermal insulation efficacy of Redwrap, a neoprene-based sleeve, during a simulated 30-minute intrahospital transport period.Design: Controlled, paired simulation study.Setting: Simulated environment conducted at the author’s residence using clinical analogs.Participants: No human participants were involved. Two saline bags were used as simulation analogs for PRBC units.Interventions: In each trial, one saline bag was enclosed in the Redwrap prototype thermal sleeve, while the paired bag remained uncovered. Each pair was hand-held for 5 minutes (simulating delivery), rested for 20 minutes on counter (bedside delay), and held again for 5 minutes (return).Primary Outcome Measures: Final surface temperature; proportion of units maintaining temperature <10°C.Results: Redrap-covered samples remained below 10°C (range: 5.6–9.2°C; mean: 7.4°C), while uncovered samples exceeded it (range: 11.7–16.9°C; mean: 15.1°C). The mean final temperature was significantly lower in Redwrap-covered samples (mean: 7.4°C) compared to uncovered samples (mean: 15.1°C), with a mean difference of 7.7°C (p < 0.001, paired t-test). Figure 1 illustrates endpoint temperatures at 30 minutes for all 20 trials, showing efficacy of the Redwrap prototype in maintaining compliance.Conclusions: Redwrap effectively maintained compliance with temperature thresholds, indicating its potential to reduce PRBC discard due to temperature. Further trials using actual blood units are recommended.