A pioneering study has found that tattooed areas of skin sweat less than non-tattooed ones. This can lead to health problems in people who have almost their entire body tattooed. During the process of fixing a tattoo on the skin, the needle injects ink into the epidermis at a rate of 3,000 perforations per minute. Far from being a harmless operation, it has now been found to damage the sweat glands, which can be a serious health problem in certain settings. An article published in the Journal of Applied Physiology. carried out by a team of seven endocrine doctors, has discovered these side effects of tattoos, using a pioneering system with which they have directly measured sweating in tattooed and non-tattooed areas of the skin. A group of tattooed volunteers were put into a 50 degree hot water suit for at least half an hour. This causes the whole body to sweat at the same time. Doctors measured body temperature, sweat rate, and skin temperature in tattooed and non-tattooed areas of the body. The data revealed that the whole body began to sweat at the same time, which means that tattoos do not damage the nervous response of the eccrine glands, which are what produce sweat. However, the amount of sweat generated by the sweat glands of the tattooed skin was significantly less than in the non-tattooed areas. In addition, the blood flow could not be measured on the tattooed skin, because the ink interfered with the instruments. The conclusion of the study is that in areas with tattoos, the sweat glands are damaged and sweat less. The University of Saarland has developed SkinMarks, temporary tattoos that allow you to control your mobile and other electronic devices. This can be a problem in people who have all or most of the body tattooed, because in episodes of heat stroke, intense exercise or excessive room temperature they can suffer collapse and other serious health problems, due to the inability of the body to regulate the temperature correctly. The study recommends that people with the majority of tattooed skin pay special attention when the body begins to sweat intensely, especially in scenarios that cannot be controlled.