I keep seeing pictures of pet turtles in various knitted costumes (so far I have seen a turtle dressed as a hamburger, and as a dinosaur), and while these are really cute, I wonder, are they okay for the turtle to wear? I would think people are only using them for photo props, but at the same time, they might not be. Are there risks to that sort of thing?
Turtles are cold-blooded animals. As such they receive heat from the sun and other ambient sources. This means that sweaters and costumes will keep them colder, not warmer.
Clothing does not make things warmer, it only prevents heat transfer. Humans become warmer with clothing because it traps the heat from their bodies; reptiles become colder because it prevents heat from getting to their bodies.
So it may be a bad idea, depending on the weather.