I appreciate the regs require fire hoods, and for something like a halogen downlighter the design temperature of the luminaire can be very significant. But it seems a bit of overkill to apply fire hoods to low wattage luminaires.
These fire hoods must be made of something really special given that they can cost more than the light fittings they are covering!
I've just fitted a couple of shallow recessed downlights in our kitchen. The wattage of the bulbs comes to 14w (that's 2x7w mini flourescent tubes), so the amount of heat involved is negligible. Doesn't even get warm to the touch.
These downlights wouldn't lend themselves to the witches hat type of hood because of their physical layout:
http://www.jcc-lighting.co.uk/functions/image/resize.asppath=c:\JCC\Products\Main\381_main1.jpg&width=250
Andrew