Patterson says the sauna culture might take some adjusting to.
"It's their social outlet," he said. "Everybody saunas. You do it after a day of work or in the weekend before you go out with friends.
"It's quite unique for Kiwis because you've got to get naked and most of us can be a little reserved. It's a culture shock, but I enjoy it. Everyone is on the same level when you're naked. "
Patterson said the whippings with fresh birch tree branches are thoroughly enjoyable.
"It's not a tough wood. It's quite soft ... It sounds painful but it actually feels nice.
"It stimulates and brings the blood to the skin."
Commonwealth Games competitor Cody Cole used Rovaniemi as a base before junior world championships.
"It's quite relaxing," he says of the birch treatment.
"But you have to be naked. Underwear is banned. Them's the rules."
The Glasgow Games begin on July 23.