(Reuters) - Dealing with the extreme humidity during the World Cup in Japan will not be child's play for any team, so Wales are keen to avoid slip-ups by splashing baby oil on rugby balls in training.
Warren Gatland's side begin their campaign against Georgia on Sept. 23, and lubricated balls are one of the ways in which the Grand Slam winners are mimicking conditions ahead of the contest in Toyota.
"We've been using wet balls and been using baby oil on them as well," Gatland said at his team's training camp in Kitakyushu on Sunday.
"We've taped them up as well and we've already been through that process in the camps we had before we've been away.
"We have been to two camps where one was at altitude and it was very hot in Switzerland, and then it was the late 30s in Turkey.
"We've done as much as we possibly can in terms of dealing with the heat. I think the humidity is going to be a factor... it's how we cope with that."
Late kickoffs on hot days will mean that players must deal with high humidity and a slippery ball.
"Players who have been to New Zealand will have experienced that," Gatland added.
"I come from Hamilton, it's incredibly humid there. We know what it's like and have players who have experienced a lot of night rugby so we feel we've prepared well."
England have also been preparing for slippery balls at their team base in the southern city of Miyazaki, with coach Eddie Jones knowing the climate well from his time as Japan boss from 2012-15.
"We have buckets (of water) on the side of the pitch and we put the ball in that before we throw it,” said England hooker Jamie George.
“We are the lucky ones because we get a towel before we throw, so we’re at least allowed to dab it down a bit. We saw it in training yesterday that the ball is slippery."