Deserts are some of the hottest, driest, and most extreme environments on Earth, with temperatures regularly reaching levels that can be hazardous to human health. The highest recorded air temperature on the planet was 134 degrees Fahrenheit (56.7 degrees Celsius) at Death Valley, California, while the Lut Desert in Iran registered the hottest ground temperature of 177.4 degrees Fahrenheit (80.8 degrees Celsius). These extremes are driven by a combination of atmospheric and surface conditions unique to desert regions.
Deserts are defined not by heat but by their low levels of precipitation—usually less than 10 inches (250 millimeters) annually. This definition includes both hot deserts, such as the Sahara and the Arabian Desert, and cold deserts like Antarctica, where temperatures can drop as low as -75 degrees Fahrenheit (-60 degrees Celsius). The location of many hot deserts aligns with latitudes of about 30 degrees north and south of the equator, due to atmospheric circulation patterns. Warm air rises near the equator and at 60 degrees latitude, where it cools and releases moisture, but sinks at approximately 30 degrees latitude. This sinking air compresses and warms, causing dry conditions and contributing to desert formation.
Several factors cause deserts at these latitudes to reach intense heat. The lack of cloud cover means the sun’s rays strike the ground unimpeded, heating the surface directly. The sandy or rocky ground also absorbs heat rapidly due to a low specific heat capacity, leading to high daytime temperatures, which can drop sharply at night. Additionally, deserts lack vegetation and moisture, limiting evaporative cooling, a natural process that helps moderate temperatures in more humid environments.
As global temperatures rise due to human activities such as fossil fuel combustion and deforestation, deserts are becoming hotter, drier, and dustier. This can expand deserts into neighboring regions, a process known as desertification. However, in some cases, shifting wind patterns have brought increased rainfall to certain deserts, including the Thar Desert in South Asia and parts of northern China, resulting in localized greening. These changing conditions alter native ecosystems, posing challenges to species adapted to desert environments.
Human health risks are particularly acute in these rising temperatures, especially for vulnerable populations such as infants and young children. Pediatric experts emphasize that children have higher metabolic rates, sweat less, and absorb heat more quickly, making them more susceptible to heat-related illnesses. With heat waves becoming longer and more frequent under climate change, caregivers are urged to take precautions when children are outdoors.
Recommendations include limiting outdoor exposure during peak heat hours, dressing children in loose, light-colored clothing, ensuring adequate hydration with frequent small feedings for infants, and using sun protection. Using canopies for stroller shade rather than blankets helps maintain airflow and prevent overheating. Metal surfaces like car seats should be checked for heat before contact. In addition, even brief exposure to parked car interiors can be deadly; approximately 31 children died from vehicle heat stroke in 2025 in the United States alone. Safety measures include leaving personal items in the back seat as reminders of a child’s presence and pre-cooling the car’s interior.
Understanding the interplay between atmospheric dynamics, land surface characteristics, and human-induced climate change is critical as deserts become hotter and more expansive, impacting both ecosystems and vulnerable populations worldwide.