The National Weather Service has issued a Heat Advisory for San Diego County Valleys - Including the cities of Escondido, El Cajon, San Marcos, La Mesa, Santee, and Poway. Temperatures in the 90s are expected. Intense heat can cause heat-related illnesses. More forecast information and updates are available from the National Weather Service. Drink plenty of fluids, stay in an air-conditioned room if one is available, stay out of the sun and check up on relatives and neighbors by telephone, video conferencing or if in person, while adhering to social distancing recommendations to prevent the spread of COVID-19. Young children and pets should never be left unattended in vehicles under any circumstances.