Originally Posted by Unabomber
Yes, that temperature is unsafe. Anything under 60 degrees turns summer tires into shopping cart wheels.
I don't notice a massive difference in the handling of the OEM Dunlops summer tires in low 40 degree temps. They definitely ride harsher and max grip and handling is compromised a bit, but they handle just as good as any other ultra high performance A/S tire I've owned. Threshold braking is fine too. I know driving around on them in low 40 degree temps isn't ideal, but it's definitely not a major risk.