I am thinking to replace the regular CFL bulb on a light fixture to a 'Smart Guardian 42-Watt Halogen A-19 Clear 6-Hour Cycle Timer Light Bulb', but because its called 'Halogen', I am little concerned about the heat that it could generate as the light figure has a glass cover dome. Any suggestions on this? I plan to be away from home while this light comes on and I dont want to take any chance. TIA. --Shiva.
A 42W bulb is only going to produce 42 Watts of heat (well, a little less since some of the energy escapes as light (roughly 3 - 5% for a halogen)).
So as long as the fixture is rated for at least 42 watts, that bulb will be fine. The max wattage limit should be noted on the fixture somewhere, either on a sticker, or embossed in the metal.
I think your fear of the word "halogen" comes from the number of accidents attributable to 300W and 500W halogen floor lamps with exposed bulbs, these concerns have been mostly addressed with new safety features (primary guards over the bulbs). But a 42W replacement bulb doesn't pose the same hazard.