A heat advisory has been issued for St. Louis County and surrounding areas through 7 p.m. Thursday, the first one issued in 2020.

The National Weather Service of St. Louis said that heat index values up to 103 degrees are anticipated.

Everyone is advised to drink plenty of fluids, stay in air conditioning, stay out of the sun and check on relatives and neighbors. Young children and pets should never be left unattended in vehicles under any circumstances.

Take extra precautions if you are working or spending time outside.

When possible, reschedule activities to early morning or evening, and be aware of the signs and symptoms of heat exhaustion and heatstroke. Schedule frequent breaks in shaded or air-conditioned environments.

Wear lightweight and loose-fitting clothing when possible.

Heatstroke is an emergency that requires a 911 call.

The counties affected by the heat advisory are St. Louis County, St. Louis City, Jefferson, Monroe, St. Charles, St. Clair, Clinton, Madison and Washington.