I've been using a NarDa with a Dovpo Rogue 100 plus for a while and I had no similar problems even with the airflow almost closed. Yesterday I bought a Pulse BF 80w and I can't hit it more than twice with the airflow wide open. It gets so hot that it burns my lips immediately. I've used prebuild clapton coils, namely a 0,50 hive coil and currently a 0.36 flat twisted coil (both of which I've also used with the Rogue ). And my battery is Ampking 3000mAh 20700. The box stays fine but the rda is too hot to even unscrew and takes a lot to cool down too. Should I be worried?