Hi.
Thanks for your query, albeit short and specific.
Noted the history about your friend having nausea, sweating, extreme hot and cold flashes,
dizziness, tired and falling asleep; thinking of food
poisoning.
All the symptoms are suggestive of
septicemia and hence I would advise you the following:
Take him to the ER or the nearest hospital.
He needs urgent clinical evaluation and examination along with investigations like that of stool, blood and urine,
Ultrasonography.
This will lead to the exact cause.
Till then proper treatment in the form of intra-venous fluids, antibiotics, symptomatic and supportive treatment can be instituted.