A City of Tempe Parks and Recreation Department employee tends to the turf as the sun comes up at Tempe Town Lake, March 19, 2026, in Tempe, Ariz.Rebecca Noble/AP
An unparalleled spell of hot weather for the month of March continues to persist across the southwestern and western areas of the United States.
Scores of March high temperature benchmarks were exceeded on Thursday in states such as Arizona, California, Colorado, New Mexico, Nevada, Utah and Wyoming.
Several communities in Arizona and California surpassed 100 degrees Fahrenheit. A few locations encountered temperatures topping all-time April highs. In Flagstaff, Arizona, temperatures hit 84 degrees, which is 11 degrees above any prior day in March’s history and 4 degrees warmer than any point in April.
Physicians informed ABC News that individuals can experience critical health repercussions during periods of severe heat, and such effects could be exacerbated when heightened temperatures arise sooner than anticipated.
"Heat compels your body to exert more effort in order to manage its temperature, and when this becomes amplified, the mechanisms responsible for temperature regulation can falter," Dr. Lauren Siewny, an assistant professor of emergency medicine at Duke University School of Medicine and medical director of the Duke University Emergency Department, explained to ABC News.
People visit Baker Beach in San Francisco, March 18, 2026.Jeff Chiu/AP
How intense heat can pose a health hazard
Typically, during intense heat – referring to conditions when temperatures are hotter or more humid than is common – the body endeavors to cool down by perspiring.
Failing to replenish with liquids may precipitate dehydration. The body’s core temperature could then escalate further, possibly triggering various heat-related ailments. Individuals might suffer from sunburn, heat rash, or heat cramps, indicated by signs like muscle aches and contractions.
More acute outcomes could involve heat exhaustion or heat stroke, a life-threatening state characterized by the body’s temperature climbing above 104 degrees and the failure of cooling processes.
Exposure to intense heat can bring about even greater harm to the organism, Dr. Kai Chen, an associate professor of epidemiology at Yale School of Public Health, informed ABC News.
"What research over the past two to three decades has consistently pointed out is that the effects of heat go beyond these specific injuries: heat stroke, accidental fatalities," Chen remarked. "It has the potential to trigger a vast range of health issues, from elevated risks of cardiac episodes and respiratory diseases to kidney failure and kidney ailments."
A study from 2022, jointly executed by researchers from both China and the U.S., ascertained that days marked by severe heat were associated with a rise in ER visits linked to kidney diseases.
Research has demonstrated that intense heat can exert effects on mental well-being, according to Chen.
A 2021 study, co-authored by Chen, identified a connection between short-term exposure to intense heat and increased ER visits for psychological disorders.
Moreover, individuals on particular medications, encompassing some antidepressants and antipsychotics, may encounter challenges in temperature management, according to the Centers for Disease Control and Prevention.
A City of Tempe Parks and Recreation Department employee tends to the turf as the sun comes up at Tempe Town Lake, March 19, 2026, in Tempe, Ariz.Rebecca Noble/AP
The Danger of Early Heat Waves
"Physiologically speaking, it requires about two weeks to acclimate to high-heat conditions, and therefore, early in the spring-summer months, when we are confronted with elevated temperatures, the body’s capacity to sweat is diminished," Siewny stated. "This increases the potential to reach critical body temperatures that could result in organ impairment."
She noted that a discordance also exists between typical safety precautions against heat-related sickness and those that are implemented at the time.
Siewny indicated that air conditioning systems might not yet be operational, individuals might not be accustomed to hydrating adequately by drinking more water, and scholastic institutions or athletic teams may not have revised their routines to consider high temperatures.
"All these elements combine, implying that these early heat waves are liable to be increasingly lethal compared to those occurring later in the year, when the appropriate safeguards have been adopted," Siewny observed.
Chen appended that research findings demonstrate that early-season heat waves frequently prove more hazardous than those arising later in summer.
A 2010 study originating from the Yale Environmental Engineering Program and School of Forestry and Environmental Studies revealed that during early summer heat waves, the likelihood of death rises by approximately 5% as opposed to late summer heat waves, where the risk elevates by only roughly 2.5%.
For safety measures, specialists suggest leveraging air conditioning or locating the closest cooling center or public establishment where air conditioning is unavailable. They further advise that people wear lightweight, loosely-fitting attire, curtail outside activities, and drink copious amounts of water.
Clive Lovejoy reads a book while lying on grass at Dolores Park in San Francisco, March 18, 2026.Jeff Chiu/AP
Chen added that long-range strategies require implementation by government officials, for instance cutting back on carbon emissions, given that a warming climate will give rise to more severe climatic occurrences.
"The past decades have marked the warmest periods on record, and regrettably, we are experiencing increasingly potent, recurrent, and premature heat waves," he expressed. "Unless we curtail our carbon emissions, these phenomena will intensify and extend beyond the South or Southwest regions of the U.S. We exist within a warming climate, and fundamentally, no means exist to avert this trend unless we diminish the fundamental impetus."
ABC News' Kenton Gewecke contributed to this report.
Sourse: abcnews.go.com