(Staff photo by Derek Davis)The first Friday of August in Maine was hot and humid enough to make you sweat just sitting there. The National Weather Service on Thursday issued a heat advisory for Friday predicting that the heat index — how hot it feels when combining heat and humidity — would get within a degree or two of triple digits. Related Heat advisory issued for much of Maine on FridayIt did just that. The Portland International Jetport recorded a heat index of 96 degrees, according to the weather service. The weather service projects that the heat should begin to fade Saturday, but it will remain hot and humid.