June 21, 2012 (CAPE COD) Dangerous heat and humidity, and the possibility of record-breaking temperatures are in the picture for Massachusetts for a second day. A heat advisory will be in effect with temperatures expected in the upper 80s and lower 90s on Cape Cod. The mercury could approach 100 around Boston. An air quality alert for high ozone levels will be in effect again for Cape Cod and southeastern Massachusetts. People are urged to not to overdo it outdoors, and to keep hydrated. Cooler weather is expected along with some storms tomorrow.