The National Weather Service has issued an excessive heat warning until 9 p.m. Saturday.

It reads:

Temperature highs are in the mid 80s to mid 90s today, and mainly the 90s Friday and Saturday. Temperatures will cool into the mid 50s to mid 60s at night. Seattle, Bellevue and those places in the Cascade Foothills that are prone to east winds will experience the milder nights.

Much cooler weather will return on Sunday.

Hot weather increases the potential for dehydration and heat-related illnesses. The elderly, the young and those who work or exercise outdoors will be the most vulnerable to heat related illnesses if extra precautions are not taken.

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.

Take extra precautions if you work or spend time outside. When possible, reschedule strenuous activities to early morning or evening. Know the signs and symptoms of heat exhaustion and stroke. Wear light-weight and loose-fitting clothing when possible and drink plenty of water.

If you plan to go boating to escape the heat, wear an approved life jacket. Drowning is the cause of most boating fatalities. Also, avoid alcohol because it impairs judgment.

The City of Redmond adds:

Seek out public buildings when possible with air conditioning like malls and libraries. The Redmond Senior Center, located at 8703 160th Ave. N.E., is air conditioned and open from 8:30 a.m. to 4:30 p.m. on Friday.

Red Flag Fire Warnings indicate that critical fire weather conditions are occurring now. Dry, hot and windy conditions can contribute to elevated fire dangers. Wildfires burn every year in East King County. Before fire dangers strike, homeowners can help protect lives and property. Visit here for tips on reducing fire risks and excessive heat safety.