Millions of Americans Experience Worst Heat Wave in Recorded History

But start with the millions of americans waking up day three under the heat dome. It's one of the worst in recorded history. Look at the map. Eight states suffocating over the excessive and oppress I... See More

But start with the millions of americans waking up day three under the heat dome. It's one of the worst in recorded history. Look at the map. Eight states suffocating over the excessive and oppress I have heat. Will it lift? Good morning. Ginger. Reporter: At least three more days of the oppressive heat and it will stick with us with the records. It's 90 in las vegas. I'm here in las vegas. 123 in needles, california, that is the hottest they've been in june ever. Sacramento to 107, 105 salt lake city, four days in a row above 100, phoenix, 119, and in vegas, going for the all-time high today of 117. Today, we begin day three of what is now a deadly heat wave. It kind of beets you up after a while. Reporter: At least one person is dead in las vegas, and dozens have been hospitalized with heat-related illness. While it tied the 115 degree record for the second day in a row, southern californians and their pets are sprinting for shade. Outside san diego, a hike got too hot. A woman had to be air rescued, sick from the heat. I remember seeing a lady, and she was like, it's hot, I don't think I'm going to be able to make it down. Reporter: And for the guy that let's us all stay comfortable, this is anything but. Very busy. We started extremely early, i don't know what time we're going to get done. Reporter: It's not just the deserts, houston had a record high of 107. Volunteers there bringing the homeless water and ice. You send the van out to make sure they know there's an op. Here's water, see you tomorrow. Reporter: In scottsdale, arizona, they are cooling off in pools and foun tans. And boulder city, nevada, these ladies are saying dry heat by umbrella. This man makes a refreshing discovery, while this puppy enjoys his favorite new spot. Ready for this? High temperatures well into the hundreds again here in las vegas, where am I again? High of 117. Phoenix, 116, death valley, 129, and, again, it does not end today, monday, tuesday, wednesday, right into the midweek, and temperatures well into the hundreds. Not just in the southwest, but seattle, a record high at 91. Boise goes to 103, and 106 on tuesday, and death valley, a quick check for our friends there that have travelled to see the heat, 129 the next two days and then starts to slip off as we head toward the all-important fourth of july holiday.