The ground on Nisyros is warm. Walk down into the Stefanos crater, the largest of the hydrothermal craters on the island's caldera floor, and the earth steams through small vents, the air smells faintly of sulphur, and the pale crust underfoot is hot enough to feel through a thin sole. Here the heat comes from below as well as from the sun overhead.

The island is small and almost round, a single volcanic cone in the Dodecanese between Kos and Tilos. Most people arrive by boat from Kos and land at Mandraki, the main village, where white houses with coloured balconies line narrow lanes that run down to a black-pebble shore. Above the village, the monastery of Panagia Spiliani sits inside the walls of the castle built by the Knights of St John in the fourteenth century, reached by a flight of steps. Higher still are Nikia and Emporios, two villages built on the rim of the caldera, looking straight down into it.

The crater floor is the part of the day that decides the shirt. It is open, white and without shade, and the light comes back up off the ground. A long-sleeved linen shirt worn loose does more here than any short sleeve: it keeps the arms covered without holding heat against them, and the air moves through the weave as you walk. The PP Laos Long Sleeve linen shirt in Oyster sits well against the grey-white crust, and it stays respectable for the drive back up to the villages. Closed shoes with a firm sole matter more than anything else on the crater floor; sandals are for the lanes.

Nikia, on the rim, is the place for the late morning. Its small square, paved in a pattern of black and white pebbles, has a kafeneio and the kind of quiet that only very small villages keep. The road to it climbs through terraces of oak and almond, and the wind on the rim is noticeably cooler than on the caldera floor. A shirt that can be buttoned at the cuff and the collar is useful on the walk along the rim path, where the view opens over the crater on one side and the sea on the other.

Mandraki is where the evening happens. Tables are set along the harbour front and in the small squares, and dinner is unhurried: local cheese, chickpea dishes, fish from the morning's boats, and soumada, the almond drink the island is known for. For him, linen trousers with a loose shirt are entirely in keeping with the village; the PP Casual Linen Trousers in Oatmeal with a Dark Blue shirt reads as considered. For her, the Amelia linen dress shirt in Dubarry works for the harbour at dusk. For the steps up to Panagia Spiliani, knees and shoulders should be covered, so the visit belongs to the morning, in the PP linen blouse with a long skirt or loose trousers she has packed for it.

Pali, a short drive along the coast from Mandraki, is the island's small fishing harbour and the nearest thing Nisyros has to a beach town. The shore is a mix of dark sand and pebbles, and the water deepens quickly. At the water, the PP natural swim shorts are the garment for swimming; the linen shirt waits on the chair for the walk to lunch.

October is a good month for Nisyros. The day-trip boats from Kos thin out, the crater can be walked in the early afternoon without the high-summer heat, and the evenings in Mandraki are mild. The island has a few small hotels and village rooms rather than resorts, so a light bag works: two or three shirts, one pair of linen trousers, one pair of linen shorts, sandals and a pair of walking shoes.

Nisyros pairs naturally with its neighbours. Kos is the gateway, and its own wardrobe across beaches and old town is a different exercise; further south, Symi's harbour of painted mansions asks for something closer to Mandraki at dinner.

Read more: What to Wear on Patmos  ·  What to Wear on Leros