on our broadcast tonight, blistering heat. a dangerous stretch continues to churn across a huge part of the country, now the longest duration in over a decade. and out west, 100-degree temperatures fueling a massive wildfire. the backlash against "rolling stone" for putting the face of the accused boston bomber on their cover. and now the growing list of big-name stores taking the magazine off the rack. the warning signs of alzheimer's. what to worry about, what not to worry about. for example, for starters, if you ever hear yourself asking, "now why did i just walk into this room?" and the big arrival in london. what is the royal family trying to tell us perhaps about when the baby might arrive? "nightly news" begins now.

good evening. from nova scotia west to michigan, from new york south to virginia, cities and towns and people are under strain because of the hottest temperatures of the summer in what is now the longest duration heat wave in a decade in at least some places. the system causing it continues to sit there, while millions bake beneath it. for a lot of the east coast cities, like philadelphia, this week, right now, is traditionally the hottest week of the year every year. and this year has decided not to disappoint. we have it all covered tonight from the widespread heat to the forecast ahead to the latest and largest heat-fed wildfire out west near palm springs. we begin tonight, however, with nbc's tom costello on pennsylvania avenue in d.c. tom, good evening. >> reporter: hi, brian. we got up to 102 degrees with the heat index in d.c. today. hottest day of the year in chicago. a lot of cities may break records. boston could break one back to 1997.

amtrak today northeast corridor delayed up to two hours because of the heat. that is going to inconvenience tens of thousands of customers. 'tis the season, but boy, is it hot outside. add in the humidity and the heat indices are at or near 100, from the lake shore in chicago to the streets of minneapolis, from the carolinas to new england. >> i come out thinking i'm going to run as as far as i usually do, but then i hit the heat and i think, well, let me scale that down just a little bit. >> reporter: in new york, two children and nine firefighters were taken to area hospitals after a fire in suffocating temperatures last night. >> it has various vapor barriers that keep the heat in and have to relieve quite often and make sure we hydrate them. >> we've got this dome of hot air, high pressure, which means that the air is sinking. >> reporter: this heat wave is extending across the country. 45 states experiencing temperatures in the 90s or above. many cities five to ten degrees above average. new york city could see the longest stretch of 90-degree weather in 11 years. even hotter for the guys working

the city food carts. >> terrible. really, i sweat like a chicken, you know? >> we need to drink a lot of water. >> reporter: after three days of extreme heat in d.c., doctors at med star washington hospital center are starting to see heat stroke patients. >> whether you're a worker with physical exertion or an athlete out there, you got to take breaks. you got to take water breaks. you got to take cooling breaks. you got to get out of the sun. >> reporter: there is good news though for hundreds of people in maryland's prince georges county who thought they would be without water through the weekend. crews now say they can fix a water main without turning off the water. meanwhile, out on the streets, making a buck means sweating a bucket. >> i need sunscreen, i need sunglasses, i need this hat and i need gatorade, man. >> reporter: this is david landerman's first week pedaling a cab. timing is everything. we checked on the status of the power grid. they tell us it's holding up well. and, in fact, it would have to get even more hot, even more humid for longer stretches of time before the power grid would in any way be considered to be unstable.

brian, back to you. >> still getting over the image of that vendor sweating like a chicken. not sure what that means. tom costello in washington starting us off tonight. tom, thanks. we normally associate weather channel meteorologist mike seidel with extreme weather, and tonight, it happens to be heat. he is live not far from us here in new york's central park. mike, good evening. >> reporter: good evening, brian. we are not setting many records. what we will remember about this week is the persistence of the heat, as tom costello mentioned. today in central park, 97 on the thermometer, the hottest day so far this summer. and there's going to be more of this. take a look at the thursday high temperatures, again, mid-90s from boston to st. louis. heat index values once again around 100. these temperatures running 10, 12, 15 degrees above average. but again, few records set. then the cooldown begins friday afternoon. cold front through the twin cities, 10 degrees colder behind the front, but it is going to feel like a jungle for many of us, including a 99 in st. louis. that front will bring gusty thunderstorms saturday to the northeast and then there's relief. and speaking of the have and have nots, in atlanta today,

finally, they cracked 90 for the first time this month. it has been nearly 40 years since the city has gone this deep into july before they hit 90. brian? >> unbelievable. mike seidel live in central park for us tonight. mike, thanks. as we swing out west tonight, extreme heat is adding to the fuel for a large and growing wildfire in southern california. outside palm springs, thousands of firefighters are now fighting this one in the heat. nbc's miguel almaguer is there for us tonight. miguel, good evening. >> reporter: brian, good evening. that billowing smoke behind me is a clear indication that this blaze is on the move. you may be able to hear those overhead choppers that are dropping water on this blaze. they are throwing every resource possible at it. while most nearby communities are safe for now, this fire remains a significant threat. this is as close as we can get to southern california's so-called mountain fire, exploding across 22 square miles of mostly wild land, at least half a dozen homes destroyed by

the fast-moving inferno. >> everything i worked for all my life is probably up in flames. >> reporter: with more than 2,000 firefighters on the ground, this is the nation's top priority fire. these parched mountains haven't burned in decades. much of this region is a tinderbox. >> we expect to have a very difficult, long fire season. the vegetation is as dry as it normally is at the end of the season. >> reporter: tonight, 17 major wildfires are burning in seven western states. today, scientists meeting in washington said climate change plays a factor in what's become a deadly and historic fire season. >> drier weather, longer droughts and hotter temperatures. we have the kind of behavior that we're seeing now that created the situation where we lost the firefighters in arizona. >> reporter: yesterday, kevin woyjeck, one of the 19 firefighters killed in arizona, was laid to rest. today, many who attended his funeral are back on the front lines.

the blaze forced 130 children with special needs to evacuate camp ronald mcdonald. and while flames closed in on pine springs ranch, firefighters took a stand at town hall and won. but this firefight isn't over yet. that plume of smoke is dropping ash on cities miles away. air quality is an issue across this region. the good news tonight, this fire is already 10% contained. brian? >> miguel almaguer in southern california for us tonight. miguel, thanks. a storm of criticism. "rolling stone" magazine is getting attacked tonight for the man on the cover of "rolling stone," the accused boston marathon bomber. it started on social media, got louder all day as the picture was distributed. now, it's affecting retail. our report tonight from nbc's john yang. >> reporter: the floppy-haired face staring up from the cover of the august issue of "rolling stone" looks like he could be the latest teen sensation. it's dzhokhar tsarnaev, the

accused boston marathon bomber, and the cover is creating controversy. >> the cover is more like a privilege. and, i mean, this guy, after what he did, it's sad. >> they are trying to make him look like a rock star. he's horrible person that did a horrible thing. >> reporter: boston mayor thomas menino said a cover story about bombing survivors would be more appropriate. >> he is a terrorist. we don't want him on our neighborhoods. we don't want him on our magazines. we don't want him anywhere. >> reporter: mbta transit officer richard donahue was seriously wounded in a shootout with tsarnaev and his brother, tamerlan, that was killed. in a statement, he called the cover thoughtless at best. tsarnaev used the picture for his twitter profile. it's the same photo that illustrated a "new york times'" front page profile in may. the goal of any cover is to sell magazines, but big retailers like drugstore chains cvs, walgreens and rite aid quickly said this issue won't be sold in their stores. in a statement, "rolling stone"

editors said their hearts go out to the victims. they said the cover story falls within the traditions of journalism and the magazine's commitment to serious and thoughtful coverage. "rolling stone" has a history of serious journalism, like the story that led to the resignation of u.s. afghanistan commander, general stanley mcchrystal. in 1970, charles manson appeared on "rolling stone's" cover, and other news magazines have had controversial covers, including hitler and osama bin laden on the front of "time." >> i think that "rolling stone" committed an act of journalism in both publishing this photo and publishing the story that they did. >> reporter: but the photo is generating strong reactions from so many. john yang, nbc news, chicago. overseas tonight, confirmation from edward snowden's lawyer that snowden has, in fact, applied for temporary asylum in russia. he did so in a very brief request, informal to say the least, handwritten, because his lawyer said this would look more convincing.

snowden hopes to receive an i.d. card within days, permitting him to leave the moscow airport finally, where he has been stuck for more than three weeks. the u.s., of course, is not happy about this. republican senator lindsey graham even suggested the u.s. consider a boycott of next year's winter olympics in russia. in great britain, the expectations are getting greater by the hour, as the world anticipates the birth of the royal baby pretty much any time now. even the queen herself had something to say about the timing. nbc's kate snow is in london tonight, watching and waiting, along with everybody else. and kate, i understand that is the hospital behind you where we will know something at some point. >> reporter: it is, brian. and about all we know right now is that at some point, kate middleton, the duchess of cambridge, will come to this hospital and give birth to a baby. what we don't know is where she and the prince are at this hour, or, indeed, her exact due date. and even the queen is getting

anxious. in northern england this morning, 10-year-old faye beatty asked the queen an important question. >> i asked her whether she would like kate's baby to be a boy or girl. >> reporter: the queen's reply? >> i don't i mind. i'm going on holiday. >> reporter: she is headed to scotland next week. the baby will be diana's grandchild, but if it were born today, it would share a birthday with prince charles' second wife, camilla, now 66. she said monday she was hoping for a birth by the end of the week. >> we're all waiting by the telephone. >> reporter: we last saw prince william at a polo match on sunday. kate has been out of sight since mid-june. the baby she's carrying will shape the future of the monarchy. >> this is the dawning of a new era for the house of windsor, a magical new time for the royal family. >> reporter: with new rules of succession replacing the old. >> completely sexist, age-old laws dating back to the 18th

century dictating that actually a first-born daughter can't take the throne if succeeded by a second-born son. that's all been scrapped. >> reporter: queen elizabeth herself wouldn't be queen at all if she had a brother, but this baby, boy or girl, will be in line to the throne, after grandpa and dad, of course. here in london, even the tourists are hoping kate hurries. >> i'm here until tomorrow night. so she needs to have it today. >> reporter: but as every mother knows, babies have their own schedule. and once this baby is born, someone will race out here and go over to buckingham palace two miles away with a bulletin for the public to put up the notice about the gender, the time of birth, the weight of the baby. and we expect, brian, because this is such a modern monarchy now, they will also post all those details on twitter and facebook. brian? >> kate snow in london who be among the first to know. kate, thanks. we will be looking for you. still ahead tonight, early detection of alzheimer's. what should you worry about in yourself or a loved one and what

not to worry about. and later, all aboard. they are making waves just to deliver the mail.

we are back, as promised, with a special look tonight at the warning signs for alzheimer's, what to worry about, what not to worry about, what's normal brain behavior and forgetfulness and what should raise a flag. doctors know more about the difference and they are better able to start treatment. our report on this tonight from our chief medical editor, dr. nancy snyderman. >> make this design for me. >> reporter: at the mayo clinic in rochester, minnesota, 63-year-old architect david cane is healthy and volunteering in a study that could help find a treatment for alzheimer's. >> begin. >> reporter: by targeting the disease at its earliest stages. >> we give medications to people, improves their memory a little bit, improves their social interaction abilities a little bit, but it really doesn't alter the long-term outcome of the disease. >> reporter: to figure out what's an early warning sign for

alzheimer's versus normal memory loss, researchers at brigham and women's hospital asked 200 healthy volunteers, ages 65 to 87, to report concerns about their own memory. each also got a brain scan, looking for buildup of amyloid plaque, a protein deposit associated with alzheimer's disease. it turns out those who were most anxious about their memory also had the highest levels of plaque, meaning people can likely sense when something is going wrong. doctors are exploring this possible connection by tracking the group to see if any get the disease. >> the implication of these findings is that it will help inform drug trials that are just getting underway. >> reporter: back in minnesota, david and his wife, linda, think their occasional forgetfulness isn't anything serious. >> he doesn't remember some of the family birthdays or anniversaries. >> i don't remember names as well as i did at one time. >> reporter: doctors say that

type of memory loss is normal. so when should you be concerned? here are the warning signs. for instance, getting lost in familiar surroundings, having trouble remembering important details from recent events, and difficulty recalling or following the plot of a tv program or book. the term is called subjective cognitive decline, that belief you know something is wrong. it's not misplacing these and wondering where the car keys are. it's looking at them and thinking what do they go to? so not to alarm anyone tonight, but if you see a repetitive pattern, that's the time to talk to your physician. because early recognition can be entry into early testing, brian. and there are a lot of promising drugs out there. >> what about the conversations that happen between couples all over this country every day where you say, you know, the movie with the guy who was in it with the blonde girlfriend and she was -- and people just go tangentially. is the standard, if it alarms you or your loved ones, it's

probably an alarming sign? >> there's a normal part of that where you can't remember people's names and you can't put things together, but if you start to see a daily pattern, or there's this disruption in life, deep down inside, what this study shows is if it starts to bother you, that's when you have the conversation. and i've talked to a lot of people said, well, i don't want to know. the answer is, yes, you do want to know, because if you can make a difference by early drugs, you want access to those. and even more important, you want to get affairs in order. you want to make sure your legal and your financial and your medical house is in order. i don't believe in putting your head in the sand and saying, oh, well, it's not good for me. knowing, there's a lot of power in that. >> all of it very helpful stuff. nancy, thank you. >> you bet, brian. we are back in a moment with a guy who opened his laptop and received the shock of a lifetime.

an ominous prediction today from the climate experts at noaa, the u.s. navy and coast guard. they fear by 2050, not that long from now, the arctic could be virtually ice-free in the

summers. they warn that as this happened, commercial activity will crowd in, tourism, roads will get built, shipping traffic will increase. they say it's coming a lot sooner than anticipated and the situation will need managing. depending on where you live, perhaps you've seen them mounted on police cars, and perhaps you've assumed they're some sort of radar gun when they are actually license plate readers. as the cruiser cruises by, they are constantly scanning and recording the license plates around them. that all goes into a massive database, searching for stolen cars, known criminals, and under the loose banner of national security. now the aclu is tracking, we are all being trakd and the lens are being used to record vehicular movement in a what they say is another erosion of our privacy rights. in order to enjoy this next item for what it is, you don't need to be a baseball fan. you don't need to be a yankee fan, which lord knows is challenging enough this season. you just need to appreciate what

happened on a hot baseball diamond in queens, new york, last night when the best there ever was came to the mound. mariano rivera, consensus hall of fame, ace closer, all-time leader in saves, retiring at 43, got a standing ovation at his last all-star game when he came in in the eighth. both benches came forward, tears welled up in his eyes. his cutter was on fire, per usual. threw a one 1-2-3 inning. was voted mvp. and for added measure, the american league won the game. a guy in pennsylvania was briefly the richest man in the world. he logged into his paypal account last friday, found his balance was just over $92 quadrillion dollars. that's a lot. it doesn't last long. he got an e-mail telling him of the erroneous transfer of funds and returning his paypal balance to zero. when we come back, a tradition dating back traditions and a mail route unlike any other in this country.

finally here tonight, while there is still mail and not everything is sent electronically, it's going to have to get delivered no matter what. you know their motto, but you may not know about the beautiful place we are going to take you to now where the key to

delivering the mail is not missing the boat. our report tonight from nbc's stephanie gosk. >> reporter: lake geneva, wisconsin, is not a bad place to land a summer job. and anna and ellie may have the coolest one of all time. their mornings begin at the post office, but this is no standard delivery. the mail travels by boat, briefly by air, finished off with a sprint. anna, ellie and their brother, keith, are lake geneva's mail jumpers. the boat never actually stops. the mail route would take too much time. so the jumpers have to be swift of foot, agile and not afraid to fall in. >> what happened? >> took too long. >> reporter: lake geneva is ringed by lavish estates, many of them built at the turn of the 20th century. this used to be the only way to deliver the mail. today, it's more tradition than necessity and even become a tourist attraction. harold freestead manages the cruise line.

>> back in 1961, we had one person, one captain, one crew and just so much a part of the history of geneva lake. >> reporter: the boat moves pretty fast and there is the occasional obstacle. someone taped the mailbox shut. >> do you think they did it just to trip you up? >> reporter: yeah. to truly appreciate the dexterity needed, there was really only one option. you want to move with the boat. don't run straight at it. >> curve with the boat? >> yeah. >> reporter: the first step is rough. that was a big jump on that one. followed by a rookie mistake. oh, no. and then a graceful recovery. ellie will soon graduate from nursing school, leaving mail jumping behind. >> i keep telling myself i need to get a big-girl job and i need to work in the hospital, not out on the water, but i'm not ready to give it up yet. >> reporter: you can hardly blame her. stephanie gosk, nbc news, lake geneva, wisconsin. >> great story to end on on a

wednesday night. thank you for being here with us. i'm brian williams. we hope to see you right back here tomorrow evening. good night. good evening, everyone. >> i'm jessica aguirre. it is bad there is no way around it but a beacon of hope tonight. a growing homicide rate has many locals feeling that san jose has fallen victim to police cuffs, increasing crime and gang warfare. but new numbers appear to paint a difficult picture and more optimistic picture. marianne favro has the details. >> reporter: there have been 29

homicides in san jose this year. but the police department has success stories to report including a decrease in gang violence. >> you've got basically high speed pursuits where suspects are discarding shotguns out the window. the officers -- there's a lot of heat on the gang members. >> reporter: the new violent crime reduction plan was launched in june. the s.w.a.t. team are focused on patrolling gang hot spots. the department says that plan seems to be working. >> you have the numbers going down and double digit reductions in violent crime and that is a step in the right direction. >> reporter: last year from january through june there were 151 gang related violent crimes. this year that number dropped to 127 during the same period. that includes robberies and