What is Extreme Heat? 

Written By Teacher: Teresa Pettitt-Kenney

Hi there! My name is Teresa and I just finished my Bachelor's degree in Environmental Science and am excited to pursue environmental education in the future! I am extremely passionate about climate change, equitable climate action, and how education can work to address these issues. 

Teaching about extreme heat and climate change can be tricky since the science is complex and the topic itself is heavy. One way to keep students engaged is by using relatable examples and plenty of visuals to show how extreme heat impacts their lives and communities. You can also incorporate fun, hands-on activities, like color absorption experiments, to help them understand the concepts. Lastly, talking about real-world solutions, like becoming a Chief Heat Officer, can make students feel empowered and show that they can play a part in tackling climate change.

Written By: MIT Environmental Solutions Initiative

The MIT Climate Change Engagement Program, a part of MIT Climate HQ, provides the public with nonpartisan, easy-to-understand, and scientifically-grounded information on climate change and its solutions.

Extreme heat is a dangerous weather condition that is becoming more common and severe as climate change warms the planet. It is the leading weather-related cause of death in the United States and a significant, and likely undercounted, cause of death worldwide. In addition to its health effects, extreme heat can damage roads, electrical wires, and other infrastructure; stress energy systems as air conditioners draw more electricity; damage or kill crops and livestock; and contribute to natural disasters like droughts and wildfires.

There is no strict definition of extreme heat or a “heatwave.” The terms are used to describe periods that are much hotter than usual for the time and place where they happen.

Climate change and heatwaves

Climate change has led to about 1.8° F (1° C) of average global warming so far. We emphasize the word “average” because this slight rise in average temperatures can cause a much steeper rise in record highs and very hot days. In recent years, weather stations around the world are recording a growing number of extreme heat events and record-high temperatures.

Climate change is also making the world more humid on average. Hot, humid days don’t just feel muggier than dry days—they are also more dangerous. The human body cools itself by sweating, and if the air is too humid, sweat cannot evaporate and the body will keep getting hotter. This condition can quickly lead to fatal heat stroke for people who cannot get to a cooler place.