Surviving Extreme Heat: Understanding the Limits of the Human Body

As extreme heatwaves become more frequent and intense due to climate change, scientists are studying the combination of temperature and humidity, known as wet-bulb temperature, to determine when it becomes too hot for normal daily activity. Recent experiments at Penn State University show that the upper limit for young, healthy adults is a wet-bulb temperature of about 87°F (31°C) at 50% relative humidity. Current heatwaves are already exceeding these limits, posing significant health risks, especially for vulnerable populations. Staying hydrated and seeking cool areas are important in high heat, but access to cooling centers and air conditioning remains a challenge for many. The evidence continues to mount that climate change is a pressing problem that requires immediate action.