By Ana Espino | Published on June 09, 2026 | 4 min read
More frequent heatwaves, record-breaking temperatures,
prolonged periods of extreme heat… Climate change is gradually turning extreme
heat into a major public health challenge. While heatstroke is one of the most
visible consequences of these events, the health effects of high temperatures
extend far beyond acute heat-related illnesses. In reality, extreme heat
influences numerous chronic diseases, increases mortality, and places growing
pressure on healthcare systems.
This issue is particularly concerning in Africa, where many
populations are already exposed to high temperatures, work outdoors, and may
have limited access to water, electricity, or effective cooling solutions. Yet
the health impacts of heat exposure remain insufficiently recognized in
clinical practice. A review published in the African Journal of Primary
Health Care & Family Medicine examines the effects of extreme heat and
the measures needed to protect the most vulnerable populations.
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When Heat Exceeds the Body’s Capacity to Cope
The authors remind us that the human body relies on several
mechanisms to regulate temperature, including sweating and increased blood flow
to the skin. However, when temperatures become excessively high—particularly
when combined with high humidity—these mechanisms can be overwhelmed. Heat then
accumulates within the body, triggering a cascade of physiological reactions
that may lead to cellular damage, systemic inflammation, and, in the most
severe cases, multiorgan failure.
The mildest forms of heat-related illness include cramps,
edema, and heat exhaustion. At the extreme end of the spectrum, heatstroke
is a medical emergency characterized by a core body temperature above 40°C
(104°F) accompanied by neurological symptoms such as confusion, seizures,
or coma.
However, the consequences of extreme heat are not limited to
heat emergencies. The reviewed data show that periods of intense heat worsen
numerous chronic diseases. Cardiovascular risk rises significantly, with
increased rates of arrhythmias, heart failure, and coronary events. One
meta-analysis cited by the authors reported a 2.1% increase in
cardiovascular mortality for every 1°C rise in ambient temperature.
Respiratory disorders, acute kidney injury, and metabolic
decompensation are also more common during heatwaves. Outdoor workers are among
the populations most affected by heat-related kidney damage.
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Particularly Vulnerable Populations
The article also highlights inequalities in vulnerability to
heat exposure. Infants, older adults, pregnant women, individuals with
chronic illnesses, and outdoor workers face a higher risk of complications.
Among pregnant women, several studies have identified an
association between extreme heat exposure and increased risks of preterm
birth, stillbirth, gestational diabetes, and hypertensive disorders of
pregnancy. Newborns are also particularly vulnerable due to their immature
thermoregulatory systems.
The authors further emphasize less visible but equally
important consequences of prolonged heat exposure. Heatwaves can contribute to sleep
disturbances, irritability, reduced concentration, and worsening of certain
psychiatric disorders. Several studies have also reported increases in aggressive
behavior and suicide risk during periods of extreme temperatures.
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What If Prevention Became Just as Important as Treatment?
This review highlights that the health consequences of
heatwaves extend far beyond the risk of heatstroke alone. Extreme temperatures
affect virtually every organ system, exacerbate numerous chronic diseases, and
disproportionately impact populations that are already vulnerable.
The authors stress the central role of primary healthcare
providers in the early identification of at-risk individuals, treatment
adjustment, education on hydration, and the implementation of community-based
prevention strategies. They also remind clinicians that rapid cooling
remains the cornerstone of heatstroke management, while conventional
antipyretic medications are ineffective in this setting.
Although this article is a narrative review rather than an
interventional study, it underscores the urgent need to integrate heat-related
risks into public health policies. As episodes of extreme heat become
increasingly frequent due to climate change, strengthening the resilience of
healthcare systems and protecting vulnerable populations may become one of the
major public health challenges of the coming decades.
About the author – Ana Espino
PhD in Immunology, specialized in Virology
As a scientific writer, Ana is passionate about bridging the gap between research and real-world impact. With expertise in immunology, virology, oncology, and clinical studies, she makes complex science clear and accessible. Her mission: to accelerate knowledge sharing and empower evidence-based decisions. 
