A combination of temperatures in the 90s and high humidity will make it feel hotter than 100 degrees in the Philadelphia area today.

The National Weather Service has issued a heat advisory from noon until 8 p.m. for most of the Philadelphia region except for Salem, Cumberland, Atlantic and Cape May Counties in South Jersey. But that does not spell relief at the Jersey Shore. The weather service says heat indexes there will reach about 100, just short of what is needed to issue a heat advisory.

The heat advisory means that hot temperatures and high humidity will combine to create conditions conducive to causing heat-related illnesses.

Anyone working outdoors should take frequent breaks and drink plenty of fluids. If possible, stay out of the sun and in an air-conditioned room. Check up on relatives and neighbors, particularly the elderly.

Officials also have issued a code orange air-quality alert for the region, which means pollution concentrations may become unhealthy for sensitive groups that include children, the elderly and people suffering from asthma or heart and lung diseases.

The weather service projects a high temperature of 95 today in Philadelphia, a degree below the record set in 1957. The heat index is projected to reach about 102.

There's a slight chance of thunderstorms tonight tonight and showers Tuesday morning. The high for Tuesday is forecast to be 91. On Wednesday, the high is expected to be 85 with showers likely during the night.

Here are symptoms of heat-related illnesses.
Handout
Here are symptoms of heat-related illnesses.