As have I.
A few years ago I was at a golf driving range with my nephew and it was very hot + mid+ 90’s. I was drinking water, and while I was hitting golf balls, it wasn’t like I walking around. I started feeling a bit light headed and then started to lose my balance and had to sit down. Even after sitting down I got a ringing in my ears and my vision started going black. I had to sit for a while with my head between my knees before it went away. My nephew also wetted a golf towel with water and put it on the back of my neck.
I also came very close to passing out while playing golf under similar very hot conditions, but I had been walking the course, carrying my clubs, a very hilly course. I played golf regularly and was in pretty good shape and I was drinking water and Gatorade but hadn’t eaten anything but a power bar earlier that morning.
I also have a lot of friends and relatives who march in Drum and Bugle Corps. Even though most competitions are held in the evening, it’s not unusual to see a couple of people pass out, especially at the end of the show. But then again they’ve been practicing all day in the hot sun.
However, it was in the low 80’s in NYC this morning, not excessively hot although I think it was still rather humid but not extremely so.
I’m not saying Hillary "fainted" or fainted because of the heat, but in answer to your question, yes, you can pass out from heat.
I had close to the same experience as you. I was standing in line, had been in the sun all day and did not eat or drink enough. We were at a sporting event.
I felt myself getting dizzy and was aware that I was on my feet, but I was swaying back and forth and the only thing holding me up was the people I swayed into that were in line in front of me and behind me.
I was taken to the shade and they gave me a cold wet towel behind my neck same as you. Then an ambulance came for me even though I thought I was okay. They were right, I was not okay.
I tried to stand and almost fell over again.
Heat stroked like that is not fun and it seemed to last. Finally after a bunch of cold drinks they let me get up and go. It was about an hour.
What I can’t understand is why they did not get Hillary Clinton immediate medical attention, sit her down somewhere.
They left her propped up against that cement bollard with someone keeping a hand on her so she would not tip over. They don’t care about her? What’s up with that? Here, just throw her in this van.