Although Finland has a broad network for mobile phones, there are some areas without signal. There may also be some smaller spots where there is interference. If this happens try to climb to a higher place or go into an open area. It may be worth removing the SIM card from your phone and then trying again to make emergency call. Different phones also differ in their coverage.
We recommend that you keep your mobile phone warm at all times and take along food and drink. Certain phone models do not work when the temperature falls below zero. You should therefore let someone know your planned route. To keep your mobile phone charged, bring along a spare power source, a spare battery or an old phone with a working battery.