PHILADELPHIA - Monday will kick off a week of heat and humidity that could bring the Delaware Valley their first heat wave of the summer.FOX 29's Sue Serio is calling for hot and humid conditions Monday with a high of 90 degrees.Expect more of the same as we get deeper into the week with highs forecasted to reach the 90s on Tuesday and Wednesday as well.Thursday will bring our best chance for a so-called "cool down" with a forecasted high of 86 degrees.For the latest forecasts and conditions, download the FOX 29 Weather Authority app.___For the latest local news, sports and weather, download the FOX 29 News app.AdvertisementDOWNLOAD: FOX 29 NEWS APP.