Diabetic ketoacidosis (DKA) is a life-threatening complication of type 1 diabetes (T1D), which without treatment leads to death. Fulminant type 1 diabetes (FT1D) is a subtype characterised by a markedly rapid and almost complete destruction of pancreatic β-cells, with acute onset leading to severe metabolic derangement and commonly ICU admission. We present a case of an 18-year-old male presenting with FT1D with two rare complications of pneumomediastinum and stress-induced cardiomyopathy (SIC) with significant myocardial necrosis. We also discuss the aetiology of the pneumomediastinum; the latest thoughts on SIC: moving beyond the simple description of 'Takotsubo cardiomyopathy'; the role of troponins in critical illness; and genetic predisposition for DKA due to FT1D.