By Tim Mastro

HARRINGTON — Fairgoers on the first day of the Delaware State Fair will be greeted by oppressive heat.

The National Weather Service issued a heat advisory for the entire state today from 11 a.m. to 8 p.m. Heat index values of 105-109 are expected. The hot temperatures and high humidity may cause heat illnesses to occur.

The heat wave is expected to continue through at least Sunday with highs well into the 90s for most of the area each day, according to the National Weather Service. Today and Sunday are expected to be the most oppressive days, it said.

Today’s forecast for Harrington calls for mostly sunny conditions, with a chance of scattered thunderstorms this evening, and a high of 95 degrees. The temperature is expected to rise over the weekend, with a high of 98 degrees on Saturday and 99 degrees on Sunday.

To combat the heat, the National Weather Service said in a release to drink plenty of fluids. It also recommends scheduling frequent rest breaks in shaded or air-conditioned environments.

The Delaware State Fair does have a First Aid station, located at the base of the M&T Bank Grandstand, which can treat minor injuries and ailments. Heat stroke is considered an emergency, 911 should be called and the individual moved to a cool and shaded location, the National Weather Service said.

Certain groups are more vulnerable to the dangers of extreme heat, such as young children and infants, people with chronic medical conditions and older adults, particularly those with pre-existing conditions, who are taking certain medications and those with limited mobility. Pregnancy can also lead to higher risk of effects from extreme heat as it has been associated with adverse birth outcomes such as low birth weight, preterm birth and infant mortality, as well as congenital cataracts.

According to Bayhealth, there are several tips to stay safe in extreme heat:

• Know when to go outside. If you must go outdoors, head out in early morning or late evening when the temperatures are lower.

• Stay hydrated. Choose water or a sports drink over sodas or caffeinated beverages. Signs of dehydration include thirst, dizziness and fatigue.

• Eat a light, well-balanced meal before going out in the heat. An empty stomach on a hot day is not a good combination. Eat foods high in water content such as fruits and vegetables.

• Sunscreen is a must and don’t forget to reapply throughout the day. Regardless of skin tone, everyone should use sunscreen. As an added layer of protection, wear a hat with a brim or use an umbrella for shade.

• There may be blacktop surfacing that can get very hot at times. Wearing closed-toe shoes is a safer choice instead of flip-flops or sandals that tend to get hot and can possibly cause blistering.