As July arrives, so does dangerous heat. Extreme heat warnings are in effect from Wednesday through Saturday for nearly all of southern New England. This isn't just a standard stretch of summer high temps. The area will see a potential six-day heat wave that will test residents' patience, air conditioners and the record books. Here is what you need to know to navigate the sweaty stretch ahead, along with a little atmospheric science explaining the thunderstorm risk in the days to come.