Sasuke, although he may not show it openly, would stay by Naruto's side to protect him. He could bring him water and make sure he is comfortable, while also being on guard in case of any threats.
His other friends like Shikamaru and Choji would also do their part. Shikamaru might use his intelligence to figure out what happened to Naruto and come up with a plan to help him recover. Choji could bring some food to keep Naruto's strength up, even if he doesn't have much of an appetite due to the fever.
His friends might first notice that Naruto is not his usual energetic self. Sakura, being a medic - in - training, would likely check his temperature and use her medical knowledge to try and bring down the fever. Sasuke, though not as outwardly expressive, would probably stay by Naruto's side, ensuring his safety while Sakura works on treating him. Shikamaru might use his intelligence to figure out what caused the high fever in the first place, perhaps by retracing Naruto's steps in the previous days.
Iruka - sensei could be an interesting option. He was Naruto's first teacher and has always had a soft spot for him. He would bring the warmth and comfort of a father figure. He might not have the advanced medical skills like Sakura, but he would stay by Naruto's side, tell him stories to keep his spirits up, and do whatever he can to help Naruto get better.
In fanfiction, it could be her best friend. Her best friend would be really worried and would stay by her side all the time. She would make sure Bella takes her medicine, gets enough rest, and has something to eat and drink.
There could also be friends who are so loyal to Naruto that they would consider following his request if they truly believe it's for the greater good. However, they would be deeply pained by it. Kakashi, for instance, might understand Naruto's selfless nature but would also struggle with the moral and emotional implications of taking his life.
Sakura would probably be the first to jump into action. As a medical ninja, she'd immediately start examining Naruto and try to figure out the cause of the fever. She might be worried but also very focused on treating him.
In fanfiction, Ino might take care of Naruto by cooking him healthy meals. She could use her knowledge of herbs and plants to create nutritious dishes that help Naruto stay strong for his training.
An oc can take care of Naruto fanfiction by having unique abilities that help the plot. For example, if the fanfic has a problem that the original Naruto characters can't solve easily, the oc with a special power can step in.
In gay stories, taking care of him for her could involve lots of things. Like being there to listen when he needs to talk, helping him through tough times, and respecting his boundaries and choices.
Naruto might initially be shocked or confused. For example, if they prank him with the fake ramen, he'd probably make a really funny face when he takes the first bite. But then he'd probably laugh it off because he has a good sense of humor.
They show him kindness and try to understand his motives. They offer support and help him find a better path.