The human body’s complex arterial and venous system carries out the fundamental function of regenerating and oxygenating the entire body. While you sleep, the heartbeat slows down consequently causing the blood pressure to decrease as well. At the same time, breathing also becomes slow and deep, in order to bring more oxygen to the blood, all thanks to the slower blood flow, in order to regenerate the tissues and eliminate the waste accumulated during the day (toxins-dioxins, dead skin, etc. – organic elements on which the mite feeds -) through the epidermis. On average, a human body expels, while sleeping, approximately 120 litres of fluids over a year’s time, precisely to fulfil this important function of expelling organic material, regardless of whether it is hot or cold (proof of this is the fact that if we made it impossible for our skin to breathe, we would die of intoxication). In fact, it was demonstrated that if you weigh a mattress after it has been used for a certain number of years, it will weigh more since, once the liquid part has evaporated, the solid organic part stays inside the mattress, so much so that demonstrations aimed at selling especially powerful household appliances used for cleaning purposes are often carried out on the mattress, since it is often one of the dirtiest places in a home. This is the reason why the life of the mattress (7–10 years) is not just tied to a structural factor, but above all to a hygienic one.