Just to generalize the previous posters' advice...
Yes, you can run reactions using materials above their flash point, but you have to be careful to avoid any sources of ignition (sparks or flames), and it is even better if you can do it in an inert atmosphere to remove oxygen as well. Without a source of ignition or oxygen, materials will not ignite even at or above their flash point.
The other temperature you have to be aware of is the autoignition temperature. At this temperature, the material will spontaneously combust, without the need of an ignition source. Try not to approach this temperature. If you absolutely have to heat something that high, be sure to use an inert atmosphere and a blast shield.