Hi Dear, Welcome to HCM. Understanding your concern. Well bluish color of the tongue usually points towards some serious condition . Most commonly it is a sign of insufficient blood supply or blood supply with less oxygen in it . So we can say that tongue with blue color represent the disease related to blood as it is a sign of cyanosis . Tingling sensation and ,numbness and cold chill further indicating something related to blood supply . It is possible that it could be a sign of Congenital heart disease , diseased blood vessels or cardiac dysfunction . But we can not rule out other conditions as well like suffocation and poisoning due to certain substance . So i would suggest you to doctor without any delay and for proper evaluation of the condition . Doctor will order blood test , ECG and also check all the vitals to confirm the diagnosis . Hope your concern has been resolved. Get Well Soon. Best Wishes, Dr. Harry