Heatstroke

Major O'Bannon and his covert commandos head to the South Pacific island of Palaloa to investigate a strange phenomenon: a radiation emission that is accelerating the effects of global warning. When they discover that it's an insidious plan of sabotage from another world, O'Bannon realizes there's only one way to stop the alien invasion and nuke them. But one false move could evaporate the planet.