I rock the donut everytime i ride, i really would not ride with out it, i wear the new evs one that can zip tie to your chest protector. as you can see from the picture, its barely noticable. i have ridden in 110-115 degree heat, and it didnt make it any hotter than it already was, i like it because it keeps your head from getting whiped around during a crash, or even a whoop section, or coming up short on a jump, if your crashing on the your side, i can see how it would stop your head from slamming into the ground...pros dont even wear chest protectors for supercross, but i bet soon you will see chest protectors and neck braces.