Having just finished university for Easter, I'm up to my eyeballs in assignments to be written, and that isn't too easy when you aren't feeling 100% conscious, let alone in the mood to write.
So far I haven't got as much work done as I'd like, but that was when using the laptop. I've found it easier to handwrite lately, as you don't have the weight of the laptop on you and you can just lay in bed and scrawl with a pen, and maybe draw a picture of a cute little flower or dragon when you are sick of writing. I've got a few pages done of my screenplay, purely through handwriting and typing up when I feel like it.
So to summarise, if you feel like cack, do the normal things - stay in bed, have medicine, have fluids, but don't stop writing! Handwrite :)
Now, I'm back to sipping some Cup a Soup. Woo.