ahhh you sure theres nothing wrong!! over heating the engine is very very bad, causes one of those dominoe affects on your wallet.. i really would get that checked out, and how long do you guess you were on the red light?
see what can happen is the thermostat could be seized shut or the waterpump not working, (to the eye you cant see anything wrong) now overheating will cause a chain of events to happen (this is personal experience after i hit the red light for only 2 seconds, thermostat)
my thermostat had to be changed,
then the housing
then the waterpump,
then the radiator
then a hose
and hopefully not my head gasket or internal engine parts, (which i dont think will happen because i only overheated for a second or two)
these chain of events happened all because of an overheat plus the fact that these wear products were bound to go anyways (talking waterpump and thermostat) the radiator only blew because when i overheated it cracked and dried out the upper spigot which i believe the return hose from the engine is clamped down. the hose i replaced for extra caution.
guys dont take chances with overheating situations, they can only lead to bad stuff, and this goes for any car, not just our bimmers.