Info about Kodokan kangeiko
http://kodokanjudoinstitute.org/en/news/2017/01/2017-kan-geiko-mid-winter-training-has-started/
It is held for the purpose of disciplining mind and body through training sessions in the coldest hours in the coldest season. It has been held for over 130 years since the early days of the Kodokan.
Do you practice Kangeiko? Does your dojo have this event?