Electromagnetic emissions from everyday wireless technologies are an ever- present environmental stressor affecting biological systems. One of the most important affected organs is the heart, whose innate electromagnetic processes are interfered with by man-made non-ionising radiation (NIR) emitted from wirelessly communicating devices. In this paper, we present the weight of evidence for such effects for multiple biological systems, including the cardiovascular system and related biochemistry. This evidence was derived from papers collated within the ORSAA database (ODEB). Experiments investigating exposures from real world devices and living near mobile phone base stations show the effects of radiofrequencies on the heart and cardiovascular system. Studies with rats and humans show changes in heart rate, lipids, blood pressure, and structure and function, as well as increases in the risk of heart tumors and cardiomyopathy in experimental animals. Significant biological effects of NIR exposures below guideline ‘safety limits’ were found in 79% (n=256) of the experimental papers and 66% (n=166) of the epidemiological papers from ODEB that investigated real world exposures. In particular, one of the major biological factors underlying heartdisease, oxidative stress, had over 100 papers showing effects (>90% of publications on this topic). The SWISS research group BERENIS found significant evidence of increased oxidative stress from NIR, even in the low-dose range. This understanding has not yet reached most cardiologists, as it is not yet included in institutional training. This paper will assist with understanding by describing plausible mechanisms underlying oxidative stress. Also presented are the classical clinical presentations for patients who are acutely sensitive to NIR exposures and a set of best practice guidelines for treating patients affected by electromagnetic exposures and generally for using technology more safely in coronary care settings. Mitigating this biological stressor could positively affect bed stays prognosis and, perhaps most importantly, preventative care.