Southern California is bracing for an unprecedented heat wave, with temperatures expected to soar above 90 degrees in various regions, including Los Angeles and San Diego. The National Weather Service has issued multiple heat advisories as record-breaking temperatures are predicted, potentially hitting near 100 degrees, especially in the Inland Empire and coastal areas. Residents are urged to stay indoors during peak heat hours and adjust outdoor plans, especially on Thursday and Friday when the heat intensity will be at its highest. This dramatic shift in weather could have significant implications for fire season and local health, with officials emphasizing the need for precautions.