. >> reporter: lee goldberg, chief meteorologist at wabc in new york, has been watching this heat tidaltack the u.s. for more than a week. >> you know, it was born out in the southwest, and then it just spread throughout the entire country. so it just stays. it breeds ititlf. >> reporter: and it is deadly. >> it just gets hotter and hotter with each passing day. >> reporter: dr. neil flomenbaum is chair of emergency medicine at new york presbyterian hospital weil cornel medical center. he says it isn't just the strength but the length of the heat wave that's the problem. >> the longer the heat remains over 90 degrees, the more people will end up in emergency departments or worse. >> reporter: our bodies simply can't process this weather. if your body temperature rises above 100.4 degrees, you could suffer from heat exhaustion, nausea, headaches, confusion. above 104 degrees, you're at risk of heat stroke, seizures, heart failure and loss of consciousness. and this time one of the real changers isn't just the daytime sun but the relentless lack of relief at night. >> all the pavement, al

they say goldberg might be driving a 1996 gold oldsmobile sedan with the california license plate no. 3 s z y o23. >>> mu indications about -- new indications about whether san francisco mayor ed lee is planning on entering the race and running for a full time. >> reporter: what the mayor told us indicates he's radically rethinking his position. san francisco groups have been pushing ed lee to run for the office this fall. women for ed lee made their pitch today. >> i'm not aware that have particular -- of that particular group. >> reporter: lee took office in january, pledging to serve only as interim mayor. >> i am sure i'm not going to run. this has not been my agenda and has not been. >> reporter: that was lee in may. this is what he told us in may. are you still firm in your decision that you will not seek? >> i am firm in focussing on the job at hand, that's what i've been firm about. >> reporter: lee said the run at movement is an expression of san francisco's appreciation of the mayor office. >> that doesn't necessarily translate into elections but there are interesting discussions going on. >> reporter: with you and whom else? >> i would just leave it at that. >> this was