Experiencing burning sensation, warm skin & skin irritation feeling on face & ears. No change meds/diet. Last time @ doc BP norm. What could be cause?

C/w vasodilatation. of arterioles increasing flow to capillaries supplying skin of areas mentioned. Arterioles, body wide, under 24/7 split second control from brain (so that we can adjust blood distribution throughout body) plus local feedback control. BP/flow into local capillaries, not main artery, the issue. Thus many issues can be involved, from blushing (embarrassment) to any kind of perceived local irritant.
Warm sensation. Those sensations without skin changes suggests vasodilatation by spices, alcohol,nicotine, sun light, wind, anxiety, fever, elevation of ambient temperature, certain medications, certain vitamins,etc. You'll have to experiment to pinpoint the cause.