And in Finnish Lapland, that means one thing: tourists are on the way, and they want husky rides.

That's becoming a problem. In 2016, the top tourist activity in Finnish Lapland was snowmobiling. Three years on, it's husky sledding. Around 4,000 huskies work in the tourism industry -- compared with just 660 reindeer.

But the sudden rise in husky rides is leading experts to warn that there are hidden costs to the popular travel activity, from animals flown in temporarily from Southern Europe, to poor animal welfare standards and dogs being put down when they reach retirement age.

What's more, the short season means that dogs are essentially out of work for eight months of the year. And with demand exploding, farms cannot afford to breed more dogs, leading to "pop-up" groups flying in from other countries, who are not monitored for welfare standards as the local breeders are.