The few times I've been to shows like that it's been hotter than hell. It was like that at Bogart's when we saw Type O. Plus, we had to deal with idiots landing on us since they were diving off the upper deck on to the crowd below since stage diving wasn't allowed. It's a miracle that I didn't punch someone in the face that night. I was getting pretty agitated with those morons after a while.
Then when I went to the Napalm/Obituary show at the Emerson. It was super hot once the mosh pit started. Plus, during Obituary's set, I was wearing two shirts: An ND "From Enslavement To Obliteration" shirt and later an ND "Life?" shirt that I bought at the merch table. I just put the other shirt over the one I was already wearing since I didn't want to walk several blocks round trip back to the truck. I bet I sweated off 10 pounds that night. It was fine when the two openers played. The crowd was just standing around and waiting for Napalm to play.

The vocalist from Dead To Fall (the band that was second on the bill. Some local band played before them), says: "I wanna see a circle pit, RIGHT NOW!" and literally 5 people started to lightly push each other in a playful/mocking fashion. They were all laughing while they were doing it.
I knew why too: Everyone was waiting for the REAL show to begin. Once Napalm came out the place exploded. I remember being in the front row because I HAD to be down front. I had waited 14, 15 years to see these guys. There was no way in hell I was standing in the back. I made it through "Unchallenged Hate", "Instinct Of Survival" and halfway through "Continuing War On Stupidity" before I gave up on standing down front. The place was packed (and holds around 400 people) so, it was like riding a wave attempting to stay upright. The mosh pit was super intense and then came the stage divers.
Screw that.

Although, I have to admit, if the Emerson had a flat floor, I probably would have stage dived too. But this place was literally an old movie theater that had been made into a music venue. So, the floor was slanted. I wasn't going to take my chances with diving on a slanted floor.
I stood by the front of house soundboard all night. I actually got on stage at one point and sat down by Mitch's cabinet, but a stagehand made me get off when I told him I wasn't part of their entourage.

But he was really nice to me about it. So, that was no big deal.
I spent the rest of the night by the side of the stage. Watching the crazies knock the monitors around (accidentally...but still) and saw one HUGE dude dive off the stage and no one caught the guy. The show didn't get stopped for that. But there was an interruption during "Suffer The Children" when a guy came up on stage from where I was, and his foot caught the cable for the mic that was on Mitch's amp. You could hear the guitar drop out instantly. Their engineer, Simon Efemey, fixed the problem in less than a minute and they started the song off again.
Obituary's set didn't have those problems BUT I do remember John Tardy yelling at the front of house soundguy that he couldn't hear anything out of the monitors. It was fixed eventually and all was well.
One thing I always remembered that happened during Obituary's set was some moron in the back yelling out: "White Power!". I heard it plain as day but the guy was ignored. I remember thinking to myself: "Yeah, you didn't have the guts to say that during Napalm's set, did ya?!" What a douche.
There was also the incident after Napalm's set. I went across the street to the McDonald's to talk them into giving me a free cup of water.

We were penny pinching to get back on gas money (Even though I DID spend 25$ on a shirt..so...yeah.

) So, I got a small cup of water and as I look down the street, I see a van that's about the equivalent of 4 or 5 house lengths away from the venue. As I began to cross the street, this freak hits the gas and flies right towards me. I freaked out, ran across the street, spilled half of my damn water and bumped into some guy. The guy wasn't angry with me but I was really pissed at the driver of the van. I flipped him off and said about a thousand swears in 10 seconds.

But I was able to drink half of the water and get back inside before Obituary started their set.
It was certainly an eventful night.