Hip fractures commonly occur in older patients, with high levels of frailty and comorbidity. Many of these patients have limited mobility before their fracture, and even after surgery, their mobility may remain limited. It is therefore not surprising that they are at a high risk of developing pressure sores, particularly on their heels, and a variety of devices and interventions have been proposed to reduce this risk. Foam or air mattresses, designed to reduce contact pressure on the patient’s whole body, are now routinely used in many healthcare systems. However, there is wide variation in their design. We developed the WHiTE 14;PRESSURE 3 trial to address the lack of evidence in this area. This is a three-arm multicentre randomized trial including health economic evaluation and recruiting patients from NHS hospitals in the UK. The trial compares standard strategies for the prevention of pressure sores with standard care plus a constant low-pressure device and with standard care plus a heel off-loading device. This annotation describes the development of this trial. Cite this article: