Cryoanalgesia involves the application of a cryoprobe to nerves (Ba et al., 2015; Evans, Lloyd, & Green, 1981). The cryoprobe has a bulb at its top that cools to temperatures of -50 to -80 degrees (Ba et al., 2015; Moorjani et al., 2001). It has been studied in post-surgery pain in patients with cancer. 

Ba, Y.F., Li, X.D., Zhang, X., Ning, Z.H., Zhang, H., Liu, Y.N., ... & Li, Y. (2015). Comparison of the analgesic effects of cryoanalgesia vs. parecoxib for lung cancer patients after lobectomy. Surgery Today, 45, 1250-1254. https://doi.org/10.1007/s00595-014-1043-9  

Evans, P.J.D., Lloyd, J.W., & Green, C.J. (1981). Cryoanalgesia: the response to alterations in freeze cycle and temperature. British Journal of Anaesthesia, 53, 1121-1127.  https://doi.org/10.1093/bja/53.11.1121 

Moorjani, N., Zhao, F., Tian, Y., Liang, C., Kaluba, J., & Maiwand, M.O. (2001). Effects of cryoanalgesia on post-thoracotomy pain and on the structure of intercostal nerves: A human prospective randomized trial and a histological study. European Journal of Cardio-thoracic Surgery, 20, 502-507. https://doi.org/10.1016/S1010-7940(01)00815-6