It does ok up to about 90* F as long as you're moving. Slow stuff sucks.
I'd recommend (it's what I'm going to do) getting a Motoport Mesh Kevlar with a Leatt collar addition.
'04 BMW R1150GSA, '08 KTM 450EXC-R, '04 KTM 625 SXC
"You had better bring an extra magazine. Yeti's amped up on weird shit are hard to bring down." Lonestar2112