When they are sick.

Kirk-
You'll bring him soup and make sure Spock is doing a good job with the ship. It puts him at ease to know that the ship is okay. And you. Sometimes he'll check on you to make sure you're not getting sick.

Chekov-
You'll help him with his work and make sure he gets rest. Sometimes you have to use a translator because he would slip into Russian.

Spock-
Spock will let you do what you want. Being a Vulcan, he always wants to meditate. You're not sure, but you think he tries to trick himself into getting better through meditation.

Sulu-
Sulu lets you do everything for him. Even though he tries to convince you he's okay.

What they do when you're sick.

Kirk-
Kirk will make sure you get lots of sleep and he will still kiss you. On the cheek at least. He'll also bring you flowers from a planet. After he confirms they aren't poisoned.

Chekov-
He'll bring you some of your old favorite books. You love Harry Potter and Lord of the Rings even though they are hundreds of years old. He'll bring you hot chocolate and tea.

Spock-
Spock will try to make you feel better. Emotions are hard and so is comforting.

Sulu-
Sulu will bring you whatever you want. He'll hug you and make sure you have enough blankets. When he's at work he'll check on you every hour.