Warm weather trend sets in for San Diegos July Fourth, dangerous heat for county deserts NBC 7 San Diego [Video]

San Diego County is expected to cool down a bit Monday before a warming trend sets in for the rest of the week and into next weekend, forecasters said Sunday.

An excessive heat warning will be in effect until at least 8 p.m. Friday, with dangerously hot conditions and highs between 110 and 118 degrees in the desert, according to the National Weather Service.

Officials advised people in those areas to drink plenty of fluids, stay in an air-conditioned room, stay out of the sun and check up on relatives and neighbors.

Authorities also reminded the public to never leave pets or children inside vehicles on days that are even a little warmer than normal, as locked cars can turn into death traps in mere minutes.

The mercury could reach as high as 119 degrees in the desert by Friday, according to the NWS.

Mostly clear conditions are expected in …