The lesson must go on!

Emily resignedly sat down on the chair of her desk that in contact with her exposed skin was very cold so much so that it made her shiver. However, this did not make her forget her embarrassment for being naked in class and she positioned herself as best she could so as not to show more than what she already exposed, so she crossed her legs and put her arms in front of her to cover herself as best as possible, but with poor results. Some classmates were already giggling and staring at her amusedly while the lesson went on with the teacher who for now did not seem to notice her state of nudity or at least so she thought, because suddenly the teacher asked bluntly "Emily, why are you without clothes in class?" then waited with a stern look for her answer.

What will Emily invent? Will she tell the truth or will she tell a more or less credible lie?