"Holmes? How are you feeling?" Watson asked softly when he came into their shared living room.
Holmes' cough and sniffles afterwards gave him the answer.
Watson sat near to him, touching his forehead with the back of his hand. "Open," he commanded distractedly. Holmes gave him the kind of look petulant children give their parents, but he opened his mouth, grumbling a bit even though Watson was gentle when he placed the thermometer under his tongue. Watson felt his pulse, peered into his eyes, and felt the back of his neck. He finally pulled out the thermometer, peering into his friend's mouth before letting Holmes close it.
"Body aches?" he asked.
"Slight," Holmes murmured.
"Sneezing, stuffy nose, sore throat?"
"Yes, yes, and yes," Holmes grumbled.
"Then I diagnose you with a regular cold. Let me know if your symptoms worsen and I will monitor you for a fever, but the best cure will be for you to rest. I can give you something if you have trouble sleeping; for now continue drinking the tea Mrs. Hudson has brought, and eat this." He held out an orange freshly peeled. "Citrus will be good for your cold."
"Thank you, Watson," Holmes murmured, taking the fruit. "Remind me to thank you when I'm feeling better."
Watson patted him on the shoulder as he stood, giving Holmes a smile. "You've never failed to, my friend."
"Watson!" Holmes called, coming into the room. "Mrs. Hudson said you're ill?"
Watson groaned. "Lower you voice, please." He coughed into a handkerchief.
"Apologies, old fellow. Are you feverish?"
"No, Holmes, it's just a cold. I'll be alright," his friend sniffed. "I've just got a killer of a headache."
"Is that normal for colds?"
"No, not really, but I'm a bit prone to them," he murmured. "I'll go to my room."
"That's not necessary," Holmes said. "If you can bear my company, I'd be happy to be nearby for you. Oh, and I brought you something. Here, eat this."
Watson took a slice of fruit, biting into it and then spitting it out, grimacing.
"Is that a lemon?"
"Yes. Citrus, Watson. That's what you said last time I had a cold: that citrus helps."
"Holmes," Watson said with a weak grin, "have you ever bit into a lemon by itself?"
"No. Why? Has this one gone bad?"
"Try it," Watson replied.
Holmes did, immediately spitting it out. "That's what lemons taste like?" he asked. "Why do they taste so pleasant in lemon pies?"
"You are the foremost detective in all England," Watson murmured, "yet you forget sugar exists."
Holmes sighed. "If I ever knew lemons were so bitter, Watson, my brain attic must have forgotten it in favor of remembering pie. My apologies. While you rest I will go out for an orange."
Watson reached out and touched his wrist. "It was a kind thought, Holmes. Why don't you donate the lemon to Mrs. Hudson and simply sit with me?"
Holmes shrugged slightly. "Would the violin help, Watson?"
"It's certainly worth a try," Watson said with a small smile. Holmes rose, fetching his instrument and beginning to play softly.
"Remind me to thank you when I wake," Watson murmured after a few minutes.
"You've never failed to," Holmes replied, but Watson was already fast asleep.
For the prompt from Riandra: Oranges and lemons.