Impotence is one of the possible health consequences of working beyond the hours you are contracted to, according to a study published in the European Heart Journal. As well as taking the lead out of your pencil, working late can also damage your heart and raise your blood pressure. According to the study of 6,000 civil servants, workers who spent three hours extra each day were 60 percent more likely to suffer from heart disease, after discounting other cardiovascular risks like smoking. However, of the 6,000 sample, only 617 (about 10%) worked three or more hours overtime per day and of these 51 contracted coronary heart disease. The small size of the high overtime group makes it impossible to projection accurately onto the population.