 Biden said he believes democracy itself is on the line this election. Tamara Keith, NPR News, Washington. In Arizona, officials say at least three children have died following separate heat-related emergencies. For Member Station KJZZ, Catherine Davis-Young has more. A 10-year-old boy died last week in Phoenix after a hike on a 113-degree day. A four-month-old girl died Friday after being taken on a boat on Lake Havasu in 121-degree weather. And a two-year-old girl died