A device the size of a wristwatch can examine sweat and spot signs of an imminent, and deadly, cytokine storm that is caused by Covid-19 and other infections. The phenomenon occurs when chemicals in the bloodstream, referred to as cytokines, reproduce rapidly and run out of control. These tiny chemicals are designed to limit and control the immune system and when they go crooked it can lead to inflammation and organ damage. Early in the COVID-19 pandemic, doctors recognized that patients who developed a “cytokine storm” a surge of pro-inflammatory immune proteins, were often the sickest and at highest risk of dying. A cytokine storm can however occur in other illnesses, such as influenza. Presently, scientists report preliminary results on a sweat sensor that acts as an early warning system for an impending cytokine storm, which could assist doctors more effectively treat patients. The researchers will present their results today at the spring meeting of the American Chemical Society (ACS). ACS Spring 2021 is being held online between April 5 and 30. Live sessions will be hosted between April 5 and16, and on-demand and networking content will continue through April 30. The meeting features nearly 9,000 presentations on a wide range of science topics.