San Fernando Valley weather

A sprinkler scene in the San Fernando Valley. (File Photo/Los Angeles Times)

Los Angeles County health officials issued a heat alert for the Santa Clarita and San Fernando valleys beginning Wednesday, urging residents to take special care when outdoors.

High temperatures in the region were forecast from Wednesday through Friday, and the alert could be extended if weather conditions don’t improve, the Los Angeles Times reported.

Temperatures were expected to hover around 100 degrees in the Santa Clarita Valley and the mid-90s to 100 in the San Fernando Valley, according to the National Weather Service. Fairly high humidity from a lingering tropical air mass could make it seem a degree or two warmer.

“Everyone should remember to take special care of themselves, children, the elderly and their pets. Extreme heat such as this is not just an inconvenience, it can be dangerous and even deadly,” said Los Angeles County Public Health Director Jonathan E. Fielding.

Officials warned that high temperatures combined with prolonged sun exposure may cause dehydration, heat cramps, heat exhaustion and heat stroke.

They also said children, elderly people and pets should never be left in vehicles, even with windows cracked, because temperatures can quickly rise to lethal levels.

Although the weather's hot, no records are expected to be broken. A cooling trend will drop temperatures into the mid-90s by Sunday.

“It’s not a huge cooling trend, but people feeling the heat appreciate anything,” said Ryan Kittell, a meteorologist at the National Weather Service.

Temperatures in the mid-80s were expected in downtown Los Angeles through the weekend and in the mid-70s at the beaches.

Still, valley schools, day camps and sports groups were urged to schedule practices and other activities in the early-morning and late-evening hours to limit exposure to the sun and heat.

Fielding said the county has more than 100 cooling centers, usually senior centers or public libraries, where residents can escape the heat during the day. Public health officials posted a list of locations online.

-- Carla Rivera, Los Angeles Times