It's getting hot out there.
As the mercury soars, so too do heat-related deaths -- whether it's a child left too long in a hot car or an elderly person stuck at home with no air conditioning -- heat proves to be a deadly agent every summer.
So, why can heat be so deadly?
RELATED: Brutal Heat Wave Scorches Southwest US
Hot weather alone is not dangerous, said Chris Minson, an environmental physiologist at the University of Oregon, Eugene. Instead, it's a combination of hot temperatures, high humidity, and often preexisting health conditions that can push a person's core body temperature to reach the danger zone of 104 F. At that point, the nervous system goes haywire, the heart experiences excessive stress, and organ systems begin to fail.
"If we can't compensate in some way for external temperatures to protect our internal temperatures, that's when things go wrong," Minson said. "If you can't release heat, you've got problems."
The human body can actually tolerate high temperatures quite well, Minson said. In experiments, people have withstood temperatures as high as 215 F for as long as 30 minutes. And with training, athletes often compete in long-distance running and biking races in desert conditions without dangerously overheating.