Why a bird cage heater?
There's a reason they call parrots tropical birds because most of them come from the equatorial region of the earth meaning that is usually pretty warm. A bird's body temperature is about 104°
One indicator that a bird is cold is when they "fluff-up". That action indicates that they're trying to preserve body heat. For years, people would introduce heat lamps near the cage. The problem with the heat lamp is never knowing how close and how long to leave it on.
The great thing about the thermal perch is that the bird can choose to get on or off it as they see fit. Plus with a range of 102 to 107° along the length of the perch your bird can find it's own comfort level. It also helps relieve avian stress.
We admit being a bit biased. Our Indian Ringneck Sunshine lived on his thermo perches for many many years regardless of the season or the temperature outside. Having sold them now for six years were convinced they're safe for your bird.
Let's start with a bird's anatomy. Birds don't have a lot of nerves in their feet. It's nature's way of allowing them to walk up and down tree branches with infinite shapes and protrusions. The warmth they are feeling is really needed from the perch and not irritating their feet in any way.
Thermo perches are suited for any sized bird. We received comments from people who ordered the small size for a flock of finches and have written to say that it's been a bit too large.
That said you really want the bird to have as much surface of their feet laid against the perch to soak up as much heat as they can't into the body. Generally with the smaller birds you'll see them "warm-up" to the perches in just a few days and snuggle their bodies against the surface to gain even more warmth