June 20, 2022 - Podcast

Episode 280 — Mapping heat risk, and digital immune twins

Many U.S. communities are experiencing record heat this summer – especially in urban areas. IU Geography Professor Daniel Johnson says cities are generally hotter than surrounding rural areas because temperatures are amplified when heat radiates from pavement and buildings. But even within cities, some residential neighborhoods get dangerously warmer than other neighborhoods just a few miles away. With rising global temperatures increasing the likelihood of dangerous heat waves, cities need to know which neighborhoods are at high risk. Within these "micro-urban heat islands," communities can experience heat-wave conditions well before officials declare a heat emergency. This is dangerous because excessive heat can lead to dehydration, heat exhaustion, heat stroke and – with prolonged exposure – even death. Johnson uses Earth-observing satellites and population data to map these hot spots, often on projects with NASA. Satellites like the Landsat program have become crucial for pinpointing urban risks so cities can prepare for and respond to extreme heat, which is a top weather-related killer. With this satellite data, Johnson and his collaborators at the CDC and NASA have found that the hottest neighborhoods are typically low-income and often have predominantly Black or Hispanic residents. According to their research, on warm summer days, low-income communities of color can experience extreme heat conditions that are often more than 10 degrees Fahrenheit warmer than surrounding areas. Johnson says there are many ways cities can use this data to help residents combat extreme heat, including guided outreach to vulnerable communities during periods of elevated temperatures and strategically planting trees and vegetation help increase shade and evapotranspiration, which helps cool the surrounding area.

In other news, an IU researcher recently published a roadmap for creating a digital twin of the immune system. James Glazier is a professor of intelligent systems engineering at IU. He says digital immune twins could offer precision medicine for a wide array of ailments, including cancer, autoimmune diseases and viral infections such as COVID-19. After publishing an initial perspective in 2021 calling for the creation of immune digital twins, Glazier co-founded the Multiscale Modeling and Viral Pandemics working group of researchers. The group recently published an 11-step guide for constructing these digital twins in Nature's Digital Medicine. Glazier says the implications of immune digital twins are vast. For example, they could be used to project disease trajectories in individual patients, allowing diagnosis before the onset of serious symptoms. They could also be used to optimize the timing of medical care, identify biomarkers and more. With this roadmap, Glazier says the actual creation of immune digital twins now seems much more tangible. He and his collaborators are working to create a global alliance to make this vision a reality.