The National Weather Service has issued an excessive heat warning for the Seattle area on Thursday and Friday as temperatures are expected to break into the 90s. NWS recommends drinking plenty of fluids, finding air conditioning, staying out of the sun and checking on relatives' and neighbors' well-being during the swelter.

Here is the NWS official warning:

... EXCESSIVE HEAT WARNING REMAINS IN EFFECT FROM NOON TODAY TO 11 PM PDT FRIDAY...

* TIMING... THE INTERIOR OF WESTERN WASHINGTON WILL HAVE HIGH TEMPERATURES WELL INTO THE 90S BOTH TODAY AND FRIDAY.

* TEMPERATURE... HIGH TEMPERATURES ARE FORECAST TO REACH THE LOW TO MID 90S BOTH DAYS IN THE SEATTLE AREA... WITH MID TO UPPER 90S POSSIBLE IN SOUTHERN AREAS. NIGHTTIME LOW TEMPERATURES WILL BE MAINLY IN THE 60S.

* IMPACTS... THURSDAY AND FRIDAY ARE LIKELY TO BE AMONG THE HOTTEST DAYS OF THE YEAR.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

AN EXCESSIVE HEAT WARNING MEANS THAT A PROLONGED PERIOD OF DANGEROUSLY HOT TEMPERATURES WILL OCCUR. THE COMBINATION OF HOT TEMPERATURES AND HIGH HUMIDITY WILL COMBINE TO CREATE A DANGEROUS SITUATION IN WHICH HEAT ILLNESSES ARE LIKELY. PETS AND FARM ANIMALS ARE ALSO AT RISK.

TAKE EXTRA PRECAUTION 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 HEAT STROKE. WEAR LIGHT WEIGHT AND LOOSE FITTING CLOTHING WHEN POSSIBLE AND DRINK PLENTY OF WATER.

TO REDUCE RISK DURING OUTDOOR WORK... THE OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION RECOMMENDS SCHEDULING FREQUENT REST BREAKS IN SHADED OR AIR CONDITIONED ENVIRONMENTS. ANYONE OVERCOME BY HEAT SHOULD BE MOVED TO A COOL AND SHADED LOCATION. HEAT STROKE IS AN EMERGENCY. CALL 9 1 1.

Here are some more tips from FEMA:

August is the hottest part of summer. The Federal Emergency Management Agency (FEMA) urges everyone to take care to protect themselves from the effects of extreme heat.

Heat kills by pushing the human body beyond its limits. In extreme heat, the body must work extra hard to maintain a normal temperature.

Most heat disorders occur because the victim has been overexposed to heat or has over-exercised for his or her age and physical condition. Older adults, young children, and those who are sick or overweight are more likely to succumb to extreme heat.

To prepare for extreme heat, you should cover windows that receive morning or afternoon sun with drapes, shades, awnings, or louvers. Outdoor awnings or louvers can reduce the heat that enters a home by up to 80 percent.

When the weather is extremely hot, stay indoors as much as possible and limit exposure to the sun. Consider spending the warmest part of the day in air-conditioned public buildings such as libraries, schools, movie theaters, and shopping malls.

Never leave children or pets alone in closed vehicles. Even at home, check on your animals frequently to ensure that they are not suffering from the heat.

Postpone outdoor games and activities, and protect face and head by wearing a wide-brimmed hat.

Drink plenty of water, and avoid drinks with caffeine or alcohol. Avoid strenuous work during the warmest part of the day, and take frequent breaks.

Extreme heat brings with it the possibility of heat-induced illnesses. Simple first aid treatment can relieve symptoms of over-exposure and even save lives.

For heat cramps, move the person to a cooler location. Lightly stretch and gently massage affected muscles to relieve spasms, and give the person sips of cool water every 15 minutes.

Heat exhaustion is evidenced by dizziness, nausea and exhaustion, as well as pale, cool skin. Get the person to lie down in a cool place and loosen clothing. Apply cool, wet cloths, and give the person sips of water.

Heat stroke can be a severe medical emergency and requires immediate attention. With heat stroke, the person will probably not sweat unless sweating from a recent strenuous activity. The person will probably have hot, red skin and a rapid, weak pulse and rapid, shallow breathing. They might be unconsciousness. Call 9-1-1 or emergency medical services, or get the person to a hospital immediately. Move them to a cooler environment and try a cool bath or wet sheet to reduce body temperature.

When heat waves strike, conditions can be dangerous and even life-threatening. Don't take chances. Use common sense, and take the proper precautions.

For more suggestions, visit www.ready.gov/heat.