Europeans are advised to get a free European Health Insurance Card (EHIC) before travelling. This does not replace health or travel insurance, but entitles you to any necessary state-provided medical treatment.
Take note of the local emergency number: 112
Finnish medical facilities are generally excellent, and each town usually has at least one 24-hour pharmacy.
Mosquitoes in late June-July are vicious. Keep little ones well covered if travelling during this time.