Researchers have developed a new test that checks a person’s sweat to monitor blood sugar levels. The sweat meter can be attached to a smartphone. The phone can then alert patients when their blood sugar is getting low. It would benefit athletes or patients who don’t get the usual warning symptoms, such as palpitations, sweating and intense hunger. Right now, the only way to check blood sugar levels is with a blood test. The sweat meter works because a diabetic patient’s sweat pattern changes when blood sugar levels are too low. “All you need to do is paste an electrode on your skin,” researcher Orjan Martinsen of the University of Oslo said in the research magazine Apollon.