Most Helpful Guy
If it were me, I wouldn't mind another text... I'd kind of like it, actually. But only if you know he's interested, which it sounds like he is from what you said.
If you want to play it safe and not risk seeming too clingy (if you want to call it that, which I don't think is an issue from what you've said), send a closed ended text message where he can reply if he wants, or not, and either way it's not awkward.
So rather than "Are you feeling any better today?", text him "Hope you're over that cold soon, being sick on the weekend sucks!" or something along those lines. That way if he doesn't want to converse, he doesn't have to... he sees you're thinking about him, but you're not bugging him, expecting him to reply and engage in a text message conversation or anything.
Subtle difference, but makes the difference between "clingy" and "thoughtful", while still providing an opportunity to start a conversation if he wants to.