Which would make a more suitable pronoun in the following sentence: them or themselves?
The boys wear sunglasses to shield them / themselves from the hot sun.
The boys shielded themselves from the hot sun with an umbrella.
The boys shielded their eyes from the sun with sunglasses.
If you are only shielding your eyes, you probably wouldn't say shield yourself but rather shield your eyes. If you are shielding your whole body, shield themselves is right.