sounds to me like early indications of anxiety, as your body prepares for stress with fight or flight arousal. If you were to describe it to someone, it would be the early indications of anxiety response building in your body and psyche...There are the classic advanced severe panic attacks (hot flashes, hyperventilation, etc) but it's not all-or-nothing - there's a range. I usually keep track of mine on a 1-10 scale.
It's good that you are so in touch with your body that you can notice it! I get it too, and what really helps is to start doing my grounding and calming exercises immediately - sitting down with both feet on the floor really feeling the floor, and breathing in very deeply and evenly and counting breaths til 10 then starting over until the feeling passes. There are a lot of somatic experiencing and other grounding techniques that can help - mostly by becoming aware of your senses and reassuring yourself of your safety. People here have suggested things like washing your face, sitting in front of a fan, holding a frozen orange or a rock that has an interesting texture, that sort of thing.