How best to heat a small grow cab?

I'm after some help on how to heat a small grow area of 2'w x 1.5'd x4'h thats in my attic. Temps are around 20 C in the day, not sure what they are in the night, probably drop to around 14 C so i want to do something before it gets any colder. I've looked at the cheap electric fan heaters, but they all seem to powerful for my small cab, they say not to use in a small area. I know you can get oil filled greenhouse heaters, but i don't like the idea of using oil indoors incase it gets knocked over or melts the blackout sheeting that lines the cab. I've seen an electric tubular heater thats 2' long and 60 watts which looks like it might do the job but I can only get them online which is the same for the electric heated pads that go under your pots. Anyone had similar problems in the past? What did you end up using?

Thanks

Peace :rasta:

SWITCH YOUR LIGHTS ON TIME TO THE NIGHT, AND LIGHTS OFF TIME TO THE DAY.

LET THE SUN HELP YA OUT HERE.

GOOD LUCK.

Sorry I should of said i'm using cfl's so they don't change the temp much.

Look for small porcelain heaters. They should make some small enough to fit in your box. I have herd of folks using them in cabs with good success. Also, a heating pad may take a little bit of the edge off.
Adieu

Cheers BlueBear, i'm gonna look for one now.

:rasta: