Contents 
HEAT:
Keep a thermostat which shows room temperature and humidity in your bird room. Generally birds can be very comfortable, according to species, in a range of 60 degrees to 80 degrees; however, at higher temperatures it is advisable to mist often. Keep in mind that "most" birds will survive for short periods much better in low temperatures than high temperatures. Do not place your birds' cage near heat registers or floor vents. If you use air conditioning, please watch the temperature.... so many deaths from too much cold draft!
You can find heat panels which attractively hang on the wall by your birds' cage and/or heating lights which can hang on cage, or insert in normal light sockets...All are very affordable and can fit into any heating problem area you may have..
HUMIDITY:
Heat and cooling affect humidity. Birds do better in avg.. to medium humidity (48-60 per cent). There are many inexpensive, excellent humidifiers on the market today, which do not contain TEFLON (dangerous) holding tanks and also come equipped with UV lights, which purify water mist as it is discharged into the air! A great investment especially for those of us with heat on(dries out the air) throughout cold winters.
LIGHT:
If it is not possible for you to have your birds in a safe, naturally bright area, then investigate the lighting available to you! There are light bulbs available to us today, which offer the benefits of sunlight and fit into our light fixtures so that no other additional hardware is needed! There are also lights available for the cage itself. Many believe these lights are necessary since our birds do not get enough of the suns' benefits through windows and indirect light. Sun light is necessary to allow certain nutrients/vitamins to be absorbed as part of a bird's total nutritional needs.