Several times a month we receive calls from clients of ours or other contractors who are concerned about the extreme heat and how this will affect the paint as its applied.  The short answer is the heat is not a problem if the paint stays wet enough long enough for the area touching it to be painted while still wet.  In other words the paint is supposed to be applied as a wet film instead of being applied in two foot wide stripes which dry before more paint is added.  A small amount of water added to the paint will keep it we long enough for an area to be painted as one film instead of multiple dry stripes.