There are more than 7,000 sirens across the country – and once a year, they’re checked.
There are two basic types of alert – the General Alert, which could mean anything, from rocket attack, earthquake or even a tsumani – yes, they’re possible on lakes.
There’s also another alarm specifically for those who live near dams – for obvious reasons.
The advice is, if you hear an alarm, then switch on the radio, or go to the government information portal ch.ch.
But if you’ve downloaded the Alertswiss app on your phone, that will also provide the information needed.
But if you hear it today between 1.30 and 2pm – you don’t need to do anything.
Voters have rejected the ‘No to 10 Million’ initiative. But commentators say the strength of the yes vote is still a cause of concern for the government.
Thousands of people across the country have taken part in feminist strike events calling for equal pay, an end to gender-based violence and greater rights for women.