To ask you could say:
1. I'm sorry, I've got a terrible fever who can't go to work. Could you please give me some time to go to the doctor.
2. could you please give me today off?
3. Can I ask for two days leave ?
4. I hate to have to ask but could I take a sick day today. I'm really not feeling well.
Response might also ask about their work:
1. Well, be sure to get some rest.
2. All right, when you feel better,please go to work tomorrow.
3. Do you feel ever feel good?(Suspicion)
4. I'm sorry to hear that. Take the day off but please pass on your daily duties to someone else.
