Much has been made about the safety issue of which there has already been a potential knee jerk reaction by banning Renault from Valencia. Some may suggest canopies to protect drivers from head injuries such as those like the one Felipe Massa endured.
I think the trouble with canopies is that the driver could end up trapped inside in the event of a crash making the extricating of a driver very difficult in emergency situations in the event of a race crash.
The driver could also get even more hot and the screen could get dirty and steamed up making the cars more dangerous than they already are.
As kimi Raikkonen said earlier, drivers accept these risks and David Coulthard correctly calls for cool heads.