Hi, Jimking:

I am not sure if I almost fainted or not. I do not know if the legs weakness, the knees almost buckling, and the dim noise are linked to fainting. I never fainted before, except when I had a seizure (I have epilepsy).

The medications I am using are:
-Duragesic (fentanyl) 125 mcg: one 100 mcg patch and one 25 mcg patch every 72 hours,
-MSIR (morphine sulfate immediate release) 30 mg: one capsule once or twice daily, as needed,
-Tambocor (flecaïnide sustained release) 200 mg: one capsule daily,
-Inderal (propranolol) 40 mg: one tablet twice daily,
-Keppra (levetiracetam) 500 mg: two tablets twice daily,
-Klonopin (clonazepam) 2 mg: one tablet once daily, at bed time, and
-Tylenol (acetaminophen) 1,000 mg: one tablet once to three times daily, as needed.

I do not drink much water because I am rarely thirsty and because I do not enjoy looking for a restroom everywhere (that afternoon, I was out, enjoying nature while riding in a friend's car). Only afterwards did I go to the supermarket.

There were times when it was hot during the car ride, but I was not hot in the air conditioned supermarket.

Thanks for your answer.