The UK-ROX randomised clinical trial tested whether routinely reducing oxygen exposure would improve outcomes in mechanically ventilated adults in the ICU. More than 16,000 patients were enrolled, with the conservative strategy targeting an oxygen saturation of about 90% and usual care left to treating clinicians. The trial successfully reduced exposure to supplemental oxygen in the conservative group, demonstrating that a lower-oxygen strategy could be implemented at scale. However, mortality at 90 days was not significantly different between the two groups. There were also no significant differences in ICU or hospital length of stay or days alive and free from organ support. The study is especially relevant because oxygen can be both life-saving and harmful. Earlier trials raised concerns about hyperoxia, but the UK-ROX results suggest that simply lowering oxygen exposure across all mechanically ventilated patients does not automatically translate into better survival. For HCPs, the practical approach is to avoid unnecessary hyperoxia while also avoiding dogmatic low targets. Oxygen should be titrated to a clinically appropriate target, with ongoing reassessment as the patient's disease and ventilation change. The finding fits CritiCARE's focus on oxygen therapy and the broader move toward physiology-guided, individualised ICU management.