I've done some very hot rides in the French alps. One time climbing Col de la Colombieré in 38C, probably the hardest day on a bike I've ever had. Darting from tree to tree then the long drag for the final few KM with absolutely no shade at all. Once it hits 38C, you cannot cool down, the temperature is warmer than your core temp, you'd need a backup car with iced drinks following you, as the pros do.
So for me the answer is yes, as an amateur. Obviously you can ride to the local shops in +38C, I'm talking about longish rides mainly.