Why did no medic tell me that flecainide can interfere with the body's cooling system . Couldn't understand why I was overheating here in Turkey until I did some thinking and realised the only thing different from last. holiday was that I was taking flecainide. I googled flecainide and overheating and sure enough it can prevent the our cooling systems from working properly no wonder I felt unwell. just thought I'd share info.