Now, summer has come and thirst is one of the most common feelings we all have to experience regularly. What makes us thirsty? There are several theories about the actual mechanism of thirst on our body. According to one hypothesis, in hot days we sweat and lose a lot of water. That is why the salt concentration in our blood increases. Our brain detects too high content of salt in the blood and sends the signals which stimulate drinking behavior. According to other theory, when we sweat we also lose water from our salivary glands. As a reaction, our mouth is becoming dry and stimulates our need for a beverage.