One hundred and thirty-six patients attending for local anaesthetic procedures in the trigeminal area were assigned to four groups. Each group was injected with the anaesthetic solution at temperatures 10°C, 18°C, 37°C and 42°C, respectively. Measurement of pain during injection was made on a numeric scale. The results show a strong relationship between the temperature of the anaesthetic solution and the pain of the injection (p ≪ 0.001). This demonstrates that warning the anaesthetic solution significantly reduces the pain felt by the patient during injection, especially at 42°C. © 1993.
Alonso, P. E., Perula, L. A., & Rioja, L. F. (1993). Pain-temperature relation in the application of local anaesthesia. British Journal of Plastic Surgery, 46(1), 76–78. https://doi.org/10.1016/0007-1226(93)90070-R