This dataset contains raw temperature measurements of the internal temperatures measured during pre-heatwave conditions around the Maternity and Gynaecology building of the Royal Berkshire Hospital. The work was a pilot scheme to understand the overheating occurring within the department and what could be done to prevent it and to improve patient safety. Sensors were deployed for 2 months (July-Aug 2018). Full details can be found in Gough et al, in review: 'Assessment of overheating risk in gynaecology scanning rooms during near-heatwave conditions: a case study of Royal Berkshire Hospital in the UK', in International Journal of Environmental Research and Public Health. This data collection would not have been possible without the help of the Royal Berkshire Hospital and its staff.