In the square below the castle in Kos town grows a plane tree that local tradition ties to Hippocrates, who was born on the island in the fifth century BC and is said to have taught beneath one of its ancestors. Its old limbs rest now on a frame of supports, and the cafés around it are busy from mid-morning. It is a good place to begin, because it shows what the island is: a Dodecanese capital with a long memory, lived in all year, a short crossing from Bodrum on the Turkish coast.

Kos is also one of the few Greek islands where a bicycle makes more sense than a car. The land around the town is flat, and marked cycle lanes run through the centre and out along the shore towards Lambi and Psalidi. Garments here have to sit well in a saddle and still look composed when the bicycle is leaned against a café wall. For men, a Bliss Linen Shirt in Sky Blue, with its long sleeves, covers the forearms on the open stretches of the coast path; a Laos Linen Shirt in Grey suits the short ride into town for dinner. Both are among the PP linen shirts, and both sit well over PP linen shorts in Navy Blue.

The Asklepieion, the healing sanctuary named for the god of medicine, stands on terraces above the town a few kilometres to the south-west. It is worth seeing early, before the stone has gathered the day's heat, and it asks for a hat and comfortable shoes rather than anything formal. From the upper terrace the view runs across the strait to Turkey. A PP Natural Set in Oatmeal is cool on the climb between the levels and tidy enough for coffee in town afterwards; it is one of the PP natural sets, shirt and shorts sold together.

The long south coast and the Kefalos peninsula in the south-west hold the island's quieter beaches. At Agios Stefanos the columns of an early Christian basilica stand above the sand, facing the islet of Kastri and its small white chapel, close enough to swim to on a calm day. The swim out to Kastri, and a hired boat around the cape, are days for the PP swim shorts in Vanille or Black.

Zia, high on the slopes of Mount Dikaios, is where the island goes in the evening. The village is a climbing street of tavernas and small workshops, and the terraces at the top look out over the sea towards the neighbouring islands. It is noticeably cooler up there after dark than in town, and trousers make more sense than shorts. PP Trousers 100% Linen in White with a Monte-Carlo Male in Vanille, its walnut buttons a quiet detail, is enough for any table in the village. Women might choose the Amelia linen dress shirt in Dubarry or the PP linen blouse in Sky Blue with cream trousers, both from the women's collection.

Kos town after dark is livelier than its villages. The harbour front under the walls of the Knights' castle fills with tables, and the streets of the centre, much of it rebuilt after the earthquake of 1933 under Italian administration, hold bars and late restaurants. A day across the strait is easy to arrange from the same harbour, and the Turkish resort opposite has its own register, described in what to wear in Bodrum. Within the Dodecanese, Symi lies to the south-east, an island of painted neoclassical houses and the subject of our guide to Symi.

The season on Kos is long. Swimming is comfortable from late May into October; July and August are hot and windy, and the north coast takes the meltemi head on while the south stays calmer. Spring, when the island is green, belongs to walkers and cyclists, and September keeps a warm sea with fewer people on the cycle lanes. A suitcase changes little across those months, only in the number of evenings that call for long trousers.

Kos does not empty in winter as the smaller islands do. When the summer flights thin out, the square beneath the plane tree is still full at coffee time, and the bicycles along the shore belong to the people who live there.

Read more: What to Wear in Patmos  ·  What to Wear in Rhodes