I often get asked in many contexts about what type of space heater is safest.  Here's my guide so I don't have to keep typing it out every time. 

Criteria

What should you look for in a heater? 

For Birds

Many common electrical appliances are coated with Teflon (aka PFTE), from toaster ovens to hair curlers.  Unfortunately Teflon can kill birds when over heated, so it's important to either (a) avoid Teflon coated products, or (b) avoid overheating the Teflon.  Since you can't know for sure if an appliance contains Teflon unless you call the manufacturer, it's best to avoid the higher temperatures that can lead to outgassing - toxic gases are released at over 600ºF (these can cause instant death in birds, and can require an emergency room visit for humans with normal health), and toxic particles are released at over 400ºF (these cause slow poisoning in birds, and can require an emergency room visit for humans with health problems such as asthma). [Houlihan, et al.  "Canaries in the Kitchen: Teflon Toxicosis".  Environmental Working Group.  http://www.ewg.org/reports/toxicteflon.  Copyright: May 2003.]

For Fire Prevention

Conveniently, it's also a good idea to avoid temperatures above 400ºF for other reasons - ever read Fahrenheit 451?  400ºF is remarkably close to the temperature at which any paper goods or cloth fabrics touching the heater will burst into flame.  So for fire prevention too you want a space heater that doesn't get ridiculously hot.  (Materials near a heater can be damaged even at lower temperatures, and some synthetic materials can burn at lower temperatures, so regardless of your heater, keep it at least 1-3" away from other things.)

Acceptable styles

These are the two general styles that I recommend due to fitting the above criteria. 

Hot oil radiator

These are shaped like an old steam or hot water radiator, but they actually circulate hot oil.  Their operating temperature is usually in the range of 120º-200ºF.  At lower settings you can flick your hand on and off the surface without causing burns, but I wouldn't suggest this at higher settings, or at lower settings hold your hand on it or put flammable items on it.  Honeywell and DeLonghi are two brands you will often find. 

Here's an example picture, from a DeLongi at Lowes, $40 at the time I checked.

Hot oil radiator heaters are good for heating a small enclosed area that isn't too drafty, like a closed office or bedroom.  They will often have thermostats on them with a 1-10 temperature setting, and switches for low/medium/high, and trial and error will be required for you to figure out what setting will maintain a comfortable temperature for you.  Keep this heater at least 1 ft and preferably at least 3 ft from walls or surfaces.  These heaters have high power requirements, so make sure to plug them directly in to the wall (I've burnt out cheap extension cords), preferably an outlet with a GFCI (I've blown fuses in older houses), and do not tamper with the grounding prong.  Your electric bill will go up with the use of this.  Consider placing a teapot with water on the top if the air dries out too much. 

Once in a rare while these will actually leak oil, either due to a faulty seal in the first place, or a split seam in an older item.  When you do your supervised test run for safety (as you should for all high-temperature appliances when you first buy them or take them out of storage), run it on an easily washed surface for a couple hours while you're at home to test if for leaks.  If it does leak, exchange it at the store you bought it for another, or call the manufacturer if it's too old for that.  Don't keep using one that leaks: the oil is highly flammable, and without sufficient oil inside the radiator it may overheat (causing the oil inside and dripping onto the floor to catch fire).  Leaks are rare though, and if you check for them there's essentially no chance of fire, so don't let fear of this possibility prevent you from buying this style. 

Ceramic block with fan

These heaters are similar in concept to traditional wire coil space heaters in that you have electricity flowing through ceramic blocks that heat up, and then a fan blows that heat out to the rest of the room.  Unlike the wire coil space heaters though, the ceramic blocks do not heat up to fire-starting or Teflon-outgassing temperatures.  The entire exterior of these are generally covered with plastic, and are comfortable to touch for extended periods of time. 

Lasko are the most popular brand of these, and here's one from Lowes for $50.

Ceramic heaters are good for heating one small part of a larger room.  Some come with thermostats in 5 Fº increments which are reasonably accurate.  Although the entire exterior is safe to touch, you should still keep other items at least 1 ft away.  Like all space heaters these will likely drive up your electricity bill.  If you have a bird, do not point this one at the cage as drafts are not recommended for birds. 

For birds only

If all you want to do is keep your bird warm, I have two things to say to that.  Firstly, healthy birds on a good diet can withstand colder temperatures than you think, as long as the change is gradual.  My thermostat is set to 62ºF when I am home and awake, and it is set to 58ºF when I am out or asleep.  My bird is in good health and on a good diet, and I give her extra food in the winter (she does eat a little bit more).  Wild birds that freeze to death in the winter actually die from a combination of factors: both cold and starvation.  They usually keep warm by shivering, which takes more energy, which requires more food, so they will only actually freeze to death if there is insufficient food.  Of course you don't want your bird to be so cold as to shiver - watch for signs of coldness such as shivering, sitting fluffed up for long periods of time, tucking one foot into her belly feathers or squatting down so her belly feathers cover both feet, and if your bird is tame feel if her feet are cold.  And also of course, not all birds are healthy enough to tolerate cold temperatures - make sure your bird has had a well-bird checkup within the last year, and is on a good diet of pellets and veggies (and if she isn't, ask your vet how to convert her so you don't accidentally starve her in the process!).  Birds with bare skin due to plucking will need special considerations for heat. 

Secondly, if all you are worried about is keeping your bird warm, why bother heating the whole room?  A thermo perch is a plug-in heated perch with a varying width so your bird can pick the part that is at just the right temperature for her.  There are many sources for thermo perches, but Doctors Foster and Smith is where I got mine ($34-$43, depending upon size). 

Who are YOU to tell me which heaters are best?

There's two reasons I know something about this subject.  In the end you should make your own decision of course, after weighing all the resources you care to find and read on the subject.  But the reasons I think I know a bit about these things are as follows.

I'm a physics teacher

I teach physics and astronomy at a community college.  I know a bit about heat, temperature, electricity, and other related science topics such as chemical reactions (Telfon off-gasing, fire).

My father's a retired electrical engineer

In his first career my father was an electrical engineer with a specialty of testing household electrical products until they failed.  Everything that can be tested will fail with enough uses, and when it comes to household electrical products they usually fail by bursting into flame.  As a result, my father became very paranoid about electrical fires, and he passed on his knowledge and some of his paranoia to me. 

Got more questions?

Leave a comment or send me an email at zandperl-AT-gmail-DOT-com.