The Fivefingers tend to get hot for me when it involves anything but trail running. One shoe that I've used on the roads that tended to stay cool was the New Balance Minimus. I believe what might have kept my feet cooler in these was wearing a good pair of moisture wicking running socks with them. What worked for me: Fivefingers trail running, New balance minimus (Trail version) for road running.
I don't own a pair yet, but I plan to get some this summer. It looks like there are a lot of combinations for sole thickness if you need more insulation from the ground. They seem like they are still refining the shoes based on how many new versions have come out in the last year, so they are probably open to customization based on your needs.
Honestly....try to not run on concrete or asphalt. It's just not that great for the foot. When the roads get hot here I just run faster and less. Basically just do wind sprints....keeps the workout short and sweet and I don't burn my feet.
VFF makes other styles with thicker soles nowadays. Lot's of minimalist/barefoot type shoes have thicker soles. There are dozens of sites with great reviews (not to mention YouTube) of these shoes.
barefoot running university
Brands include Merril, New Balance, Vivobarefoot / Terra Plana, the thinnest Nike Free's are kinda close, etc.