readings, well over 100 and spreading. 107 in d.c. tomorrow. 105 in philly. 107 in chicago. it will last into the weekend. it will be warmer by saturday. tonight, authorities are warning this combination of heat and humidity could be life threatening. abc s alex perez in chicago. reporter: tonight, that heat wave has more than half the country sweltering after lightning-packed deadly storms rocked the northeast. torrential downpours turning new york s subways into waterfalls and sending thousands at this outdoor event scrambling for safety. in connecticut, a lighting strike sending a large tree limb crashing onto a car. the driver rushed to the hospital. he did not survive. this as heat, humidity and stifling air smother much of the country. feels like 108. maryville, 109, this is serious. reporter: in wichita, it felt like 108 degrees wednesday, a