Hi, Thanks for writing to Health Care Magic, I am Dr Asad Riaz, I have closely read your question and I understand your concerns, I will hereby guide you regarding your health related problem. lisinopril is used for multiple purposes like in Heart failure , for hypertension , diabetic nephro pathy etc .. it s side effects are hyper kalmia , cough ,angioedema, confusion , dizziness n so on.... as u r working on construction side .. the sweating due to heat are more likely the cause of ur dizziness rather than lisinopril , Bcs it doesn t causes heat exhasuion, it is due to Bcs of sunny day that causes it .. I advice u to drink much mineralated water and also take breaks during work to avoid heat stroke a much dangerous condition of over heating .. I hope this answered your question, if you have more feel free to ask. Regards. Dr.Asad Riaz. General and Family Physician..