The National Weather Service has issued an Excessive Heat Warning for San Diego County Valleys effective until?Thursday, 10/1/20, at 8:00 p.m. Dangerously hot conditions with temperatures 15 to 20 degrees above average will be seen through Friday. More forecast information and updates are available from the National Weather Service. Extreme heat will significantly increase the potential for heat-related illnesses, particularly for those working or participating in outdoor activities. 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. Take extra precautions if you work or spend time outside. When possible, reschedule strenuous activities to early morning or evening. Know the signs and symptoms of emergencies like heat exhaustion and heatstroke, visit:  www.sandiegocounty.gov/hhsa/programs/phs/extreme_heat Several County facilities will be open as Cool Zones. For location information, hours of operation, and tips to beat the heat, visit: www.coolzones.org.