Hi, exposure to oil paint fumes/smell in a closed garage,many a times creates allergic symptoms & seems to be the same in your friend s case.I understand your concern. Please don t worry, he will be alright with following care. - Avoid to do spray painting,if possible. If it s a must let your friend wear mask/let the shutters be open for good ventilation. -Let him take rest. nausea/vomiting can be taken care of by sipping ice cold milk slowly/ice cream licks. If that is digested ,he can start having non spicy,bland ,light to digest diet gradually. A pill of metoclopramide can be taken with a bit of watwer,to be followed by light diet after half an hour. Antacid like gelusil MPS 2 pills sucked will relieve him of pain in stomach/chest. -The dry cough is again a sign of allergy.. He acn take anti allergic cough syrup ( Benadril Cough syrup) for it. * If there is no relief with above things/if the cough is accompanied by sputum or breathlessness thanks