Experienced yesterday bluish fingernails then tingling sensation on right hand/fingers minutes or hrs after. then gradually left hand/fingers.

Raynaud's phenomenon: Is similar to this, though there is usually pain instead of tingling. This typically happens in response to cold, but you are in the Philippines. You could also have had something that decreased the circulation to your hand, such as a blood clot or some blockage at the armpit area by a tight garment or backpack or even a rib. If it happens again, you should be examined AT THE TIME.