I typically don't get the flu, but when I did get it in 10th grade, I remember feeling really really really cold, and then a couple minutes later I was sweating hot, like fire hot. And then right back to freezing cold. And it was up and down like that for a while. When I had covid, the symptoms came on gradually.
My last experience with covid was when I was sleeping, and awoke and had chills. I instantly thought, okay, I'm sick. This was friday night, the week of Christmas, and we had off work saturday, sunday, monday and tuesday. When I woke up saturday, my entire head and face hurt. Like it was being crushed. That lasted into some time on sunday, but when I woke up on monday I was stuffy, smells were coming and going, by wednesday I was feeling better, so went to work all that week with a mask (just makes everyone around you feel better so whatever, no big deal)
I didn't get tested, but had a really good feeling it was covid.