My Son-in-law Is 38 Yrs Old. Has Been Sick Since

My son-in-law is 38 yrs old. Has been sick since Friday. Symptoms are diarrhea one time vomiting several times but has been asleep since Friday night. Can't wake up. Won't drink fluids. Fever 101.6but has been asleep almost 48 hrs. Complains of muscle aches backache and headache. My daughter doesn't know what to do. Any suggestions