Switzerland packs an unusual range of climate into a small country. Southern Ticino, near the Italian border, gets genuinely hot in summer, with the same heatstroke risks as anywhere in southern Europe — watch for heavy panting, drooling, or lethargy, and keep walks to early morning or evening.
At altitude, dogs can experience a milder version of altitude sickness too — reduced energy, faster breathing, or reluctance to move much for the first day at a high alpine base. Build in an easy first day after a significant elevation gain, the same way you would for yourself.
In winter, cold pavement, road salt, and ice between paw pads are the more common everyday risks, especially for short-haired breeds. Paw balm or dog boots, and rinsing paws after a salted-street walk, are standard practice for Swiss dog owners through the winter months.