LOS ANGELES (AP) — There's a dangerous but basic equation behind the killer Yarnell Hill wildfire and other blazes raging across the West this summer: More heat, more drought, more fuel and more people in the way are adding up to increasingly ferocious fires. Scientists say a hotter planet will only increase the risk. More than two dozen wildland fires are burning from Alaska to New Mexico, fueled by triple-digit temperatures and arid conditions.