I seriously doubt that will present a problem. It will depend on the length and quality of the extension cord in this case, but I think even a cheap $1.99 6' cord would be fine.
The potential for fire, (other than arcing, which is a different topic) is caused by running too much current (amps) through a device- whether it be a wall receptacle, power strip or extension cord. Current causes heat, heat makes fires.
So, how to determine if you are running too much current? Simple math.
Amps = Watts/Volts
Most devices will tell you their maximum current rating.
In your case, you have a 125w fluoro which is ~ 1amp.
88w of cfl which is ~2/3 amp.
and your fan, lets say it's 600w, that would be 5 amps.
You are at around 7 amps, and that's not going to melt anything with 120vac pushing it. You need to figure out how many watts or amps that fan is using to be sure, but I think you get the idea.
Good luck! Have fun!
I just realized that I'm assuming you are in North America...if you are in Europe, cut those amp figures in half.
