Some 20 states are under 2heat alerts today and a few of the 3impacts might be surprising. 

Around Las Vegas, it's so hot glass has been 4shattering. 

"That 5pane that's 6facing the sun can actually get up to close to 300 degrees. When the glass starts to 7expand, it has nowhere to go."

The heat's also 8impeding aircraft. It reduces lift by making the air less 9dense. The National Park Service says that 10prevented a helicopter rescue in California's Death Valley recently. Airlines say they've had to change flight times to cooler hours of the day. In Oregon, officials say the heat is 11contributing to 12smog. 

"Try to avoid having an 13idling engine. If you need to refuel your car, do so 14at a time, like a cooler time in the evening." 

Temperatures in California are affecting how produce grows. 

"When we get these 15extreme temperatures like this, we see a lot of our 16produce- whether it's fruit and nuts as well as vegetables- they can actually slow down a little bit on the 17ripening side." 

Experts say cows make less milk when it's hot, and to them, this summer has been boiling. 

"I believe cows, they get hot at about 68 degrees, so this time of year 18is really hard on them."