A dangerous heat wave is expected to affect multiple regions in California and Nevada this week. San Diego County and Encinitas will experience excessive heat from Wednesday to Friday, with coastal areas under a heat advisory. The Cool Zones program offers air-conditioned spaces for vulnerable residents. Las Vegas is also under an Excessive Heat Warning with temperatures reaching 106°F, urging residents to stay hydrated and avoid direct sun. Northern California cities such as Sacramento and Stockton have opened cooling centers to combat triple-digit temperatures. Orange County cities, including Rancho Santa Margarita and Mission Viejo, will also see temperatures up to 104°F, with cooling centers available for residents.