The patient has been a labourer for many years so we can assume some sort of Kidney Deficiency, and we’ll use the rest of the signs to figure out what kind.
If there are just cold hands and feet, this can be Yang Deficiency or Liver-Qi Stagnation (“the groom had cold feet”), but a cold body and limbs indicates there is cold (likely from Yang Deficiency).
The purple tongue is showing Blood Stasis, and this can either be due to Blood Stasis as the primary, due to Liver-Qi Stagnation causing Blood Stasis, or Cold or Yang Deficiency causing Blood Stasis. A pale tongue shows us there is either Cold/Yang Deficiency or Blood Deficiency.
So far we can combine these signs and symptoms to come up with Kidney-Yang Deficiency. We know the Heart is involved and that spontaneous sweating with everything else going on shows us there is a Heart-Yang Deficiency (which, when written, implies a Kidney-Yang Deficiency).
I hope that explanation helps.
So! The points are: UB15 + moxa, CV8 + moxa on salt, CV6 + moxa, PC6
HT8 is a Spring acupoint. Spring points Clear Heat either from Excess or Deficiency-Heat. We don’t want to Clear any Heat with this Heart/Kidney-Yang situation.