Small boats are easily swamped in strong winds, and the seas are so cold that your chances of swimming even a short distance to shore would be tiny. Flotation suits give you a few extra minutes to contemplate death should your boat sink. Even if you do make it to land, the chances of being rescued before you become hypothermic are minimal. There is a lifeboat-style rescue service, but it comprises only four boats for all of Greenland. Even helicopter rescues can take several hours - as well as tens of thousands of dollars - to reach you.
Polar bears are very rare and they generally avoid humans. Where they are a hazard locals will advise you to carry a gun and might lend you one. If you're cornered by a bear when unarmed, try to keep your cool.
Be careful how you store food when camping, to avoid attracting foxes.
Major summer annoyances are clouds of mosquitoes, midges and mini-flies, which seek out eardrums, shoot up nostrils and make kamikaze attacks on eyeballs. They're at their worst in July, especially on wilderness hikes, when a head-net is virtually essential. Head-nets are widely sold for around Dkr40, some designs working best when worn over a baseball-style cap. Insects are curiously absent in sheep-farming areas.