You'll find two main types of heated pet beds on the market: electric and self-warming. If you're looking for a true heated pet bed, an electric model is your best bet. Electric heated pet beds work much like electric blankets. They feature a heating element inside that safely warms the bed to a moderate heat, usually around your pet's body temperature. Electric models need to be plugged into a power outlet to work.

Self-warming pet beds, on the other hand, don't require electricity or any kind of power. They simply use your pet's own body heat to keep the bed warm. They may feature a polyester layer that reflects your pet's body heat back to him or heat-retaining materials that keep warmth in the bed. Sometimes, both are featured.

Think about the size of your pet when selecting a heated pet bed. Some beds are specifically listed as dog beds or cat beds. Cat beds will, of course, be to correct size for an average cat (or a small dog). Dogs, on the other hand, vary widely in size, so there's no one-size-fits-all dog bed option. Instead, you'll need to check the dimensions and figure out whether a particular heated pet bed would be large enough for your dog to rest comfortably. If in doubt, measure your dog first.

Heated pet beds are available in a range of styles. The most common varieties are bolster beds (those with a raised edge), either rectangular or round, and flat mattress beds. The right bed style for your pet depends on how they prefer to sleep. The majority of cats sleep curled up in a ball, so they prefer round beds with raised sides. The same goes for dogs who tend to sleep curled up. A dog who likes to sleep completely stretched out, however, may prefer flat mattress-style heated dog bed. Keep in mind that some dogs stretch out but also like to rest their head on something; these dogs may prefer a rectangular bolster bed.

Some beds only heat to one temperature: they're on when plugged in and off when unplugged. However, a large number of heated pet beds allow you to select a temperature within a set range. The majority of power controls are simple and intuitive, usually with one button to raise the temperature, one button to lower the temperature, and an on/off button.

Concerned about leaving your heated pet bed on all night? You may want to choose a model with automatic shut-off. This type of bed automatically switches itself off after a set amount of time, which can range from one to eight hours.

An important concern with electric pet beds is that your pet could chew through the wire and get an electric shock. In the most severe cases, this could result in electrocution. Luckily, the vast majority of heated pet beds have no-chew wires. These are generally enclosed in a steel casing or similar, so it's virtually impossible for your pet to chomp through them. That said, if your pet has a track record of chewing wires — or destructive chewing in general — an electric heated pet bed might not be the best option.

You'll find heated pet beds in a range of colors and patterns, from plain black or beige to hot pink leopard print. Generally, each model is available in several color options, so once you've picked a heated pet bed, you can choose your favorite color option. We wouldn't recommend choosing a heated pet bed based on color or pattern alone, however.

Even the cleanest of pets have their own special odor, so beds and bedding need to be cleaned regularly to keep your house smelling fresh. The best electric heated pet beds allow you to remove the heating element from inside, so you can wash the main body of the bed either in the machine or by hand. At the very least, a heated pet bed should have removable washable covers.

Basic heated pet beds cost somewhere in the region of $15 to $25. This includes small electric models and some self-warming options.

Mid-range heated pet beds are priced between $30 and $60. You can find some excellent options in this price range, but you might not find models suitable for extra-large dogs.

High-end heated pet beds cost between $60 and $100. This includes the largest electric models, plus some high-quality smaller options.

• Choose a heated pet bed that would be comfortable for your four-legged friend. A well-padded model is a must. Memory foam options are the most comfortable and supportive.
• Consider where you'll position the bed. It's best to put your pet's bed somewhere they feel comfortable and like hanging out. Notably, the bed location may depend on whether the bed is intended for sleeping or daytime lounging. If you opt for an electric model, you'll need to position it close to a power outlet.
• Occasionally check your heated pet bed for signs or wear or damage. A heated pet bed with holes or frayed wires may not be safe to use, so it's important to monitor its condition.
• Select a durable heated pet bed. You might want to save money, but this is the kind of purchase where you should go to the high end of your available budget. Your heated pet bed will get frequent use, so it must be durable enough to withstand regular wear and tear.

Q. Could I buy a heated pet bed suitable for outdoor use?
A. Yes, you can find heated pet beds that are suitable for outdoor use in a sheltered area or inside an outbuilding or garage. An outdoor heated pet bed is great for dogs or cats who enjoy spending time in the yard even in cold weather, or for feral or semi-feral cats you look after.  However, you should not place a heated pet bed outdoors in the elements unless the manufacturer states that it is safe to do so.

Q. Are heated pet beds safe?
A. Some people are reluctant to buy electric heated pet beds, as they're concerned about a fire risk. You should know, however, that the technology used in these pet beds has come a long way since your grandma's fire-hazard of an electric blanket. While there's a minute fire risk with any electrical appliance, a heated pet bed is about as safe as a kettle or a toaster. That said, we recommend opting for a model that has undergone relevant safety testing.

Q. Will using a heated pet bed increase my power bill?
A. Heated pet beds use a tiny amount of power, usually around four to eight watts, so a heated pet bed is unlikely to add more than a couple of dollars to your energy bill, even if used daily.