I have been sweating a lot at work an feeling hot, weak and nauseous while coworkers were cold.i had blood test, it came out normal.what could this be?

Could be thyroid.: This sounds like a hyprethyroid issue, particularly thyrotoxicosis. The symptoms fit, and your blood test might not have included thyroid hormone. Get a more extensive endocrine work-up by your doctor fast with TSH levels since this can be an acute situation, like thyroid storm which would require quick treatment and have serious complications. I would see your doctor fast.

Thyroid disease: Make sure blood tests specifically checked thyroid, as well as for anemia.

Need more informatio: How old are you? What is your gender? What blood tests were done? How frequent are the symptoms, etc? If the symptoms have been there for a couple of weeks or longer, it is time to see your doctor.