Southern Nevada cities and Clark County have launched an emergency alert website that allows residents, businesses and visitors to receive free emergency alerts via their cellular phone and e-mail. Sign-up is quick and easy. Visit https://sonevada.onthealert.com/ and enter up to three phone numbers and two e-mail addresses. You can also choose what kind of alert you want to receive including extreme temperatures, flash flooding, earthquakes, air quality advisories, winter storms and hazmat incidents.