The National Weather Service has issued an excessive heat warning for the Santa Clarita Valley and most of Southern California to be in effect from Friday morning through Monday evening.

The service forecasts dangerously hot conditions with high temperatures between 95 and 108. The hottest locations will be in the far interior sections and the L.A. County valleys.

Extreme heat will significantly increase the potential for heat-related illnesses, particularly for people working or participating in outdoor activities.

Overnight low temperatures will remain very warm, only cooling into the 70s and even lower 80s, warmest in foothill locations.

The only areas of the region not affected by the alert are coastal Ventura, Santa Barbara, and San Luis Obispo Counties.

Residents should be prepared to drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors. Take extra precautions if you work or spend time outside.

Young children and pets should never be left unattended in vehicles under any circumstances. This is especially true during warm or hot weather when car interiors can reach lethal temperatures in a matter of minutes.