Romeo's smile dropped a little, "Are you ill?" He looked carefully at Sherlock, "We should go to the infirmary, because some illnesses can be cured." He was worried, the more he looked the more that Sherlock looked ill.

"But Doctor Casella says that the longer you wait the less chance doctors have of being able to make you better, so you should go to the infirmary!" Because otherwise he might die and Romeo didn't want him to die!