There are still a fair few lighting fittings in use where changing to LED or CFL lamps (bulbs) is impractical, for example track or suspended lighting systems. If replacing halogen lamps in these fittings then take care to install the correct wattage lamp. For example many smaller light fittings have a maximum incandescent/halogen rating of 40 Watts. Some of the ceiling lights arrays used in kitchens only take 35 watt lamps. Fitting an brighter higher wattage lamp will very likely result in the light fitting to overheat resulting in damage to the fitting, early failure of the fitting, possibly an electrical fault and in a worse case a fire.
Checking the maximum rating of replacement lamps that can be fitted is an important safety measure.