The voltage in Switzerland, as in most of Europe, is 230V/50 Hz. Switzerland mainly uses type C (2-pin) and Type J (3-pin) plugs. (Type C 2-pin plugs also fit J sockets.)  

 

Most power sockets are designed for three pin round plugs. The standard continental type plug with two round pins, applied for many electrical travel products, may be used without problem. Type F plugs (widely used in the EU) are NOT compatible with the Swiss sockets: https://www.iec.ch/world-plugs. Adaptors during IChO 2023 will not be provided and are the individual responsibility of the travellers.