As practice shows, it is absolutely safe in Kardamena. However, when traveling to the mountainous areas of the island, try not to exceed the speed limit - on serpentines you should keep your eyes on the road.
Another danger that may be waiting for you here is the overactive sun, as well as "creepers" in places remote from the beaches.
And never drink tap water - there is a problem with it in Greece.
It should be noted that, hundreds of migrants arrived on Kos every day, which could not but affect the deterioration of the overall situation on the island.