Lay summary
Therapeutic hypothermia is routine care for babies with brain injury due to low oxygen at birth. In randomised clinical trials, it has been shown that hypothermia improves survival without disability in babies with moderate or severe brain injury. However, babies with mild injury were not included in these trials, so the balance of risk to benefit is unknown for this group. There is growing evidence that such babies are at risk of disability and some are already being treated outside clinical guidelines. Hence, it is vital to ‘look before we leap’ and establish an evidence base before subjecting this much larger group of babies to hypothermia, intensive care and parental separation. We propose focused preclinical studies in a large animal translational model of mild brain injury to evaluate the use of less aggressive treatments to improve outcomes. Findings will inform the clinical trials that are required before therapeutic hypothermia is offered to all cases.