<s>[INST] Hi,I m a 50 y/o female in fair/good health and about 20 lbs. overweight. Last late summer I had a few episodes of what I thought was heat exhaustion and actually went to the ER once. I stayed hydrated, rested often, took frequent breaks in the shade or air conditioning, etc., but it still happened. Now that it s getting warm again (it s sometimes in the 80 s now), I m starting to have the same problem. Yesterday it began when I was working inside (the house was about 75 degrees). I am taking Vesicare, Omeprazole, and Seroquel and have Sarcoidosis (but it s in remission at present). I have made sure I take all the preventative measures when in the heat, but it seems to happen anyway. The symptoms start with head pounding, increased heart rate, weakness. Then I feel sort of dizzy and somewhat nauseated. If it continues, the head pounding increases and I then begin to feel somewhat disoriented, very tired, more dizzy, and then it will progress to fainting if left untreated. I have also had a few occasions where I get in the car with the air on, start to feel better, drive home, then when I get out of the car, it hits me again when I stand up and begin walking. After a bad episode, I will feel exhausted sometimes for hours afterwards. I did ask my Urologist about the Vesicare as a possible cause, but he said it wasn t. Any ideas why and how I can cure this problem? [/INST] Hello, I understand your concern and would explain that your symptoms could be related to orthostatic hypotension.  For this reason, I recommend you to closely monitor your blood pressure values and performing a Head-Up Tilt test in order to exclude possible orthostatic hypotension.  It is also important for performing some blood lab tests (thyroid hormone levels for thyroid gland dysfunction, blood electrolytes for possible imbalance, complete blood count for anemia).  Hope I have answered your query. Let me know if I can assist you further.   </s>