Yes, portable car heaters do work, but it is best to look at reviews of different kinds before purchasing them. Make sure to check whether it is simply a car heater or a car defrost/defogger.
no, you will have too order them online,
Most car heaters do not exceed 300 watts.
Portable heaters can use a lot of power. In fact, if you have a home from the 1950's or earlier you may need to avoid using portable heaters at all.
Radiation.
Portable car heaters can be purchased from a variety of different retailers including car and auto stores (such as Canadian Tire), online through retailers such as Amazon or Ebay, or second-hand from retailers that sell used car parts.
Yes they work great when they are below a window because of the cold air infiltration.
Heaters work best set on floor allowing the hot air to rise through the car and heat more air.
Depending on what kind of infrared heater you want, there are many retailers that carry them. Home Depot has portable infrared heaters and infrared ceiling heaters. Safer Wholesale sells portable infrared heaters and patio infrared heaters.
EdenPure makes portable infrared heaters. You can find them online at: www.edenpurestore.com
Portable heaters are safe to use in the manner written on the heaters instructions. Some portable heaters are meant for use outdoors only, so using those heaters indoors would not be safe. The other thing to consider with heater safety is do you have children who might accidentally touch the heater, if you do you need to make sure that your heater does not heat up enough to burn the child. Also, its important to make sure that your house's electrical system is properly grounded so that your portable heater, if it is electrical, does not short out.
One can purchase Calor gas heaters. Calor gas fires are portable, and they create heat and warmth whenever one needs it. They are cheaper than heaters that heat the whole house and are portable heaters.
Portable electric heaters are recommended by the U.S. Department of Energy. They also published a couple of guidelines one can follow when buying electric heaters. Some top brands are Holmes, Lasko and Seabreeze.