RUKA, Finland, Nov 28 (Reuters) - Temperatures below minus 20 degrees centigrade saw Norway"s cross-country ski team and Finland"s Iivo Niskanen skip Sunday"s men"s World Cup 15km freestyle race, leaving the field free for Russia"s Alexander Bolshunov to cruise to victory. The freezing conditions in Finland saw Sunday"s racing postponed until the early afternoon but, with the Beijing Olympics on the horizon in February, many racers preferred to withdraw from the competition. "They have warmed up and made an evaluation. It"s bitingly cold, and for that reason they have chosen to skip the race for their health. We"re not risking any sickness," Espen Bjervig, manager for Norway"s cross-country team told reporters. Niskanen, who won Olympic gold in Pyeongchang in 2018 in the men"s 50km race, summed the situation up briskly. "It"s not too long to the Olympics, minus 23 is too much for me. A simple choice," he told Norwegian newspaper VG.