Truck drivers, some of whom have appeared on the History series “Ice Road Truckers,” take their extreme driving skills to much warmer climates, but the working conditions are no less treacherous in this “IRT” spinoff. In trying to prove they’re the best drivers in the world, the truckers head to India to take on the extreme mountain roads of the Himalayas, where they have to navigate some of the oldest and deadliest highways in existence. The series also showcases the truckers hauling cargo in Bolivia and to sites high in Peru’s Andes mountain range.