As California enters its fifth year of severe drought conditions, forest fires are blazing, resources are being tapped out and residents are forced to flee.

But there are some that can't escape the heat. Trees that stand in the path of these wildfires are subject to inevitable burning. At the same time, they are becoming even more vulnerable to bark beetles.

Bark beetles invade California trees and suck out their sap, killing them and leaving them behind only to fuel the spreading fires. Bark beetles are native to California and thrive in warm temperatures and on water-starved trees. Additionally, the bark beetle population is multiplying as they lay their eggs under layers of bark.

With all these factors in play, the result is a vicious cycle of making the fight against these forest fires harder. In an attempt to tame the rapid spreading, fire-fighting helicopters take an aerial approach. However since this has quickly depleted water resources provided by state reservoirs, they now have to fly farther to refill their tanks. In return fires are given more time to spread, and become harder to contain, according to a release.

Currently, more than 100 wildfires are burning in the West, according to NBC News. This includes areas of California, Oregon, Colorado, Montana and Idaho.

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