Few choose to get hurt, but for those that do sustain an injury it is better to do so during the daytime rather than the night. Not because there are more medics around but because wounds heal more quickly. The numbers speak for themselves: a study carried out by the UK’s MRC Laboratory of Molecular Biology involving 118 patients who were treated for burns, showed that those who were burned during the night time took 28 days to heal; while those who sustained their wounds during the day took just 17 days to recover. It is all down to skin cells called fibroblasts, the human body’s equivalent of paramedics, which are the first to reach a wound and begin the healing process. The researchers believe that fibroblasts are not primed to react during the night as they are during the day, hence the difference in day/night time healing times. As researcher Dr John O’Neill explained to the BBC, “It is like the 100m. The sprinter down on the blocks, poised and ready to go, is always going to beat the guy going from a standing start.” As well as providing advice on the best time to fall over and graze your knee, the findings have serious implications for the treatment of wounds and injuries. For example, the application of a steroid known as cortisol could be used to reset a patient’s body clock so that surgery could take place at night, allowing fibroblasts to be on alert to start the process of closing the wound. Or invasive procedures could be scheduled for the daytime rather than at night. Dr John Blaikley, a clinician scientist at the University of Manchester, said: “Treatment of wounds costs the NHS around £5bn, which is partly due to a lack of effective therapies targeting wound closure. By taking these [circadian factors] into account, not only could novel drug targets be identified, but also the effectiveness of established therapies might be increased through changing what time of day they are given.” In short, ensuring fibroblasts are cranked up to full blast.