A compromise — #17 of 31 Flannel ranks #17 of 31 fabrics for excessive sweating. It is a middling fabric for this. Ranked on breathability and moisture handling, penalised for weight. The top pick is Merino.
Flannel measures 58/100 for breathability, 12% moisture regain, 80/100 warmth, at 260 gsm. For excessive sweating, modest breathability and strong moisture absorption decide comfort — and its higher warmth risks trapping heat against the skin.