Hot is moodiness and temperment I have a hot tb he's a gelding but is SUCH a drama queen he'll throw hissy fits and spook and nothing and is very sensitive on the aids. He isn't bad just sensitive, it doesn't matter what he's eating he acts the same when he is 150 lbs under weight as when he is getting energy packed food. Hot is just another term for highly strung. Palomino is a breed and a colour, the breed is a bit more tempermental as are tbs due to inbreeding for certain characteristics. Stock qhs are going to be quieter than running qhs and gaited breeds are in general hotter than qhs and percherons. But there are individuals in every breed/colour of excellent nature so don't rule anything out just because of what it looks like! Good luck!
My first horse was a Morgan/ QH. Maggie was the absolute best horse I've ever ridden. And has a kid, I put her through hell! We would ride double all over the place, jump ditches, barrel race, anything I would ask...she would do. Unfortunately, she became infected with a very rare foot fungus (i think) called canker. She had it in all four feet. After a year and a half of soaking everyday and seeing every vet around (and no one had a clue about what it was and how to treat it) we gave her to some people that were going to try some old Native American treatments on her.. If that didn't work, they were going to put her down, since it would have been really tough for my family to. We never heard anything else about her but I would assume the treatments didn't work. But anyways, she was a wonderful wonderful horse and I miss her terribly. I have heard that QH/Morgan crosses are wonderful.