Amid record-breaking heat waves , doctors caution that some of the most vulnerable people dying from extreme heat — infants — can easily get overlooked. Last week, a 4-month-old child died after developing a heat-related illness on a boating trip in Lake Havasu, Arizona, according to the Mohave County Sheriff’s Office. The peak temperature in the area that day was roughly 120 degrees Fahrenheit.

Extreme heat has become a more pervasive threat in recent years, as high-temperature days get more frequent and intense due to climate change. Pediatricians and child safety advocates say babies are dying needlessly as a result. The rate of extreme heat deaths among infants in the U.

S. is higher than the rates for children, teens or young adults, though it remains low compared to other causes of death. From 2018 to 2023, 69 infants died of extreme heat — nearly 2 deaths for every 100,000 infants in that time, according to an NBC News analysis of data from the Centers for Disease Control and Prevention.

The figure includes deaths in which heat was both a contributing factor and an underlying cause. Heat deaths are often underreported, either because they are not identified by a medical examiner or are incorrectly coded on death certificates. Pediatricians point to several reasons why infants are more susceptible to illness or death from extreme heat.

Some are biological: Babies tend to overheat faster than older children and adults, and they have a harder time cooling themselve.