Weather officials are warning residents about heat-related illnesses as triple-digit temperatures are expected to affect parts of Southern California, including the Inland Empire.

KCAL News has previously issued a Next Weather Alert for the high temperatures and heat in the metro, valleys and deserts on Wednesday and Thursday. After our team of meteorologists evaluated changing forecast data, the alert was changed to remove the Los Angeles and Orange County metropolitan areas on Thursday.

While conditions will still be warm on Thursday, they will be below our threshold for an alert and do not meet KCAL's Next Weather Alert criteria.

The National Weather Service said Wednesday will be the hottest day of the week with a high-pressure ridge positioned over the region. The coasts will have conditions in the 80s and the valleys will be in the 90s. Weather officials said there is a 30% chance that some valley communities will reach 100 or 101 degrees.

A heat advisory has been issued for a portion of southwest California, including the San Fernando Valley, Santa Monica Mountains and Agoura Hills until 9 p.m. on Thursday.

The extended period of hot weather will increase the risk of heat-related illness, especially for vulnerable populations like young children and the elderly.

Symptoms of heat-related illnesses include high body temperature, vomiting, dizziness, confusion and hot, red, dry, or damp skin. Officials urge residents to call 911 if these symptoms appear. Heat stroke is a medical emergency.