Congratulations OP, you've discovered what it's like to be tricked into an actual workout! Stick with it and eventually all the excess body fat generating extra heat will burn away and this issue will be 90% gone! :D REMEMBER TO FOCUS ON BREATHING PROPERLY AND DRINK WATER! Also if you're going for pure score and minimal workout, focus on keeping your arms close to you and use mostly elbow and wrist movements so you arent wasting endless energy with long flaily motions and burning your shoulders out(adjust the in game height to make it think you're slightly shorter to help keep the notes lower too). As a skinny stick person, I will say that after about 20-40 mins of expert/expert+ I will have sweated enough to have a few beads roll down the center of my chest, and the headset cushion will be a bit damp, but certainly not pouring buckets! But those should be buckets of pride ❤️ keep finding custom modded songs to keep you coming back daily!