What is vomiting and diarrhea symptoms of?

Usually, it is a stomach infection or food poisoning. A simple workable solution is to continuously drink ORS water or salt-sugar solution in small sips to avoid dehydration. Avoid heavy meals and stick to simple rice kanji or curd rice.

I totally get it, vomiting and loose motions at the same time is absolutely exhausting and draining. It's usually a stomach infection. Please take rest, keep sipping water, and don't push yourself to do any work today.

I think it could be stomach flu or maybe bad street food. Is it normal to feel very cold and shivery when this happens, or should we go to the hospital immediately? I am a bit worried about my roommate who is sick.

These symptoms point toward an acute gastrointestinal infection, viral rotavirus, or bacterial food poisoning. When we face this, we immediately visit the emergency ward of a good hospital to get IV fluids if needed. Ask your doctor clearly about the cause instead of self-medicating.