It's not fun.
It starts with warm cheeks, and then suddenly I can feel it spread and intensify. Its like extreme blushing...but on steroids. Just when I think it must have reached peak intensity, it ramps up a gear.
I've learned that trying to control it just ends up making it worse, so I just pause and wait for the moment to pass.
The other, chilly, evening I had to take an arm out of my jumper to try and help the heat dissipate. I couldn't take the jumper off because the rest of me would have been too cold.