By Sani Khamees
Background
Climate change is a critical global challenge, with rising temperatures harming human health. Increasingly severe extreme heat causes more disease and death, affecting physical and mental health and leading to fatalities, especially during heatwaves. As extreme heat events grow more frequent, understanding how humans respond to high temperatures is vital. Extreme heat can cause dizziness, fainting, sleep issues, respiratory problems, heat exhaustion, heart attacks, and kidney damage. Recent statistics indicate that worldwide, heatwaves have been responsible for approximately 12,000 deaths annually over the past decade. When we consider Kano State’s escalating temperatures alongside these global figures, the urgency of addressing local climate challenges becomes starkly evident.
Kano State, in Nigeria’s North West, is densely populated with over 16 million people and covers 20,131 km². It faces an increased risk of heat-related illness due to overcrowding. Its hot semi-arid climate experiences temperatures of 25°C to 35°C, which have risen steadily since the 1960s (Badamosi, 2014). Classified as BSh (Subtropical Steppe), Kano experiences high temperatures and low rainfall. Spring (March-May) is particularly hot, with temperatures reaching nearly 38.2°C in April, increasing health risks. Notably, Kano experiences approximately 250 heat-related hospital admissions per 100,000 residents annually, underscoring the significant threat posed by rising temperatures. This metric underscores the urgency of targeted adaptation funding to mitigate the impact of extreme heat on community health.
The dangers of extreme heat/temperatures
Exposure to extreme temperatures that exceed the body’s thermoregulatory capacity can cause physiological damage and the onset of heat-related illnesses (HRIs). In simpler terms, when the body overheats, organs begin to strain, and entire systems can fail. Heat exposure disrupts the body’s temperature regulation mechanisms, often leading to acute fever. Mild forms of acute HRI include heat cramps, heat edema, heat syncope, and heat tetany (Barrow & Clark, 1988, p. 58). These conditions represent the initial symptoms of heat injury and may progress to heat exhaustion, the most prevalent type of HRI. During heat exhaustion, core body temperature ranges from 38.0°C to 40.5°C, with symptoms such as malaise, anorexia, nausea, and vomiting. Major neurological deficits are typically absent at this stage. If thermal damage intensifies and core body temperature exceeds 40.6°C, heat stroke may occur, which is an acute and potentially life-threatening syndrome. Heat stroke is defined as a condition in which body temperature rises to a harmful level, resulting in dysfunction and damage to body tissues and a characteristic multi-organ clinical and pathological syndrome (Epstein, Y. and W.O. Roberts, 2011). Even after recovery, patients may experience permanent damage to the central nervous system or other organs.
Engaging in excessive physical activity in hot environments can elevate body temperature above the body’s capacity for heat dissipation. Without timely treatment, heat stroke may result in permanent damage or become life-threatening. Heat exposure not only directly causes certain diseases but also exacerbates chronic conditions. The most pronounced impact is the worsening of cardiovascular diseases. Heat waves are associated with increased incidence of heart failure and myocardial infarction. Heat-related cardiovascular conditions contribute to higher rates of emergency hospital admissions and account for a significant proportion of deaths, including those occurring outside hospital settings (Schwartz, J et al, 2004). Notably, Kano State experiences significant economic impacts due to these conditions, with cardiovascular-related hospitalizations accumulating substantial healthcare costs each year. Quantifying these expenses can underscore the urgent need for implementing more robust cooling infrastructure to alleviate the financial and health-related burdens of heat waves.
Beyond cardiovascular disease, elevated temperatures are closely associated with respiratory health risks. As core body temperature increases, the body attempts to dissipate heat by increasing lung ventilation, resulting in thermal tachypnea or thermal hyperpnea (White, M.D., 1985). Excessive hyperventilation at high core temperatures can lead to alveolar hyperventilation and respiratory alkalosis, potentially causing tissue damage (Richards, S. 1970). Higher temperatures also increase the movement of particulate matter in the air, intensifying respiratory system impacts. In Kano’s dust-laden air, particulate matter concentrations are particularly elevated, exacerbating these respiratory challenges. Furthermore, climate change has extended the pollen season and increased pollen concentrations, leading to a higher incidence of allergies and compromised respiratory function (Dominici, F., et al, 2006).
Heat exposure risks pregnant women and newborns. Pregnancy-related changes reduce temperature regulation, increasing heat-related health risks. High maternal temperature and heart rate can cause fetal tachycardia and contractions, risking premature birth. Kano clinics could schedule prenatal visits during cooler times and offer hydration stations to prevent dehydration. Research shows heat causes dehydration and increases hormones linked to preterm birth (Baharav, Y., et al 2023).
Climate change poses environmental and mental health crises (Lawrance, E.L., et al., 2022). Temperature shifts affect mental health by disrupting physiological processes, like blood flow and CNS function, leading to cognitive and emotional issues (Lõhmus, M., 2018). Higher temperatures increase mortality among those with mental illness (Thompson, R., et al., 2018). Some psychiatric medications impair thermoregulation, worsening health during heat exposure.
Extreme heat affects mental health directly and indirectly, impacting both current and future populations through various pathways. Climate change plays a role alongside social factors like reduced productivity, increased conflict, and violence (Lawrance, E.L., et al., 2022). Vulnerability is heightened by adverse effects of some psychiatric medications, reduced behavioral adaptability in mental illness, and heat-induced sleep disturbances that worsen mental health issues.
Heat wave in Kano
Kano State faces significant health challenges due to its large, densely populated area. Kano city alone has approximately 4 million residents within 449 km² (Statista, 2026), resulting in urban congestion-related issues. Industrial and vehicle emissions have contributed to biodiversity loss and climate change, including higher temperatures and more frequent heat waves. As one of Northern Nigeria’s fastest-growing urban centers, Kano grows at 3% annually. The city’s population density is approximately 1,000 people per km², and its climate is classified as wet and dry by Köppen. Abdullahi et al. (2020) found elevated carbon emissions in Kano Municipal at (1577 ppm) and Kumbotso (1839 ppm), levels that meet the UN standards for poor air quality. The highest temperatures recorded were 40°C in Nassarawo and 39°C in Tarauni. These findings align with studies in other Nigerian cities, such as Kaduna (Zakka S.D., 2018), the housing sector (Ezema, Opoko, and Oluwatayo, 2016), and Ibadan (Eluwa S.E., 2014). The research shows long-term environmental impacts of rapid urban growth, calling for further detailed study. Indoor emissions slightly surpass outdoor levels, mainly due to small plot sizes, congestion in poorly planned settlements, and the use of generators, wood fuel, and charcoal. Temperatures range from 23°C to 40°C across the area. Measurements of outdoor carbon monoxide at seven key junctions identified Sharada Junction as the highest at 25 ppm. Traffic counts reveal that Nasarawa Local Government has the highest traffic volume, with 18,957 vehicles (Abdullahi et al., 2020). Creating a heat-pollution overlay map could vividly highlight these hotspots, guiding city planners to target interventions that reduce health risks. Such visual notes can effectively highlight neighbourhoods requiring urgent action.
Call for action
1. Heat acclimatization helps reduce heat wave impacts by gradually exposing the body to higher temperatures, promoting safe adaptation. For instance, spending 20–30 minutes daily on light outdoor activities as spring warms can boost heat dissipation. It can reduce the risk of heat-related illness, potentially reducing the risk of heat stroke by up to 50%. The body maintains a core temperature of approximately 37°C through sweat evaporation, but extreme heat can overwhelm this process, leading to heat stress. This forces the body to work harder, straining organs and increasing the risk of heat-related illnesses.
2. To effectively reduce the impact of these disasters, comprehensive early warning systems are essential. meteorological forecasts and real-time data analysis can be used to help authorities quickly alert communities about imminent heat events, giving them time to prepare and adapt. Public awareness campaigns support these efforts by informing citizens on preventive steps like hydration, cooling locations, and recognizing heat illness signs. Using digital media, radio, and TV ensures broad communication.
3. Creating and promoting cooling centres is vital during heat waves. These public spaces, like libraries, community centres, and schools, offer refuge for vulnerable groups including the elderly, children, and those without adequate home cooling. They provide quick relief and act as community hubs strengthening social ties in extreme heat. A notable example is Kano Central Library, which functions as both a library and cooling hub. During last summer’s intense heatwave, it opened to the public, offering a cool environment, educational resources, and workshops on heat coping. The initiative gained strong support and serves as a model for other neighbourhoods. Planning should ensure these facilities are well equipped and staffed, especially during prolonged heat waves.
4. Effective urban planning and infrastructure upgrades are vital for reducing heat-wave risks. Green elements such as parks, urban forests, and green roofs help lower urban temperatures by providing shade and natural cooling through evapotranspiration. Green roofs also reduce energy bills by insulating buildings, supporting environmental sustainability, and encouraging investment in cool-city design. Reflective roofing and pavement materials, known as ‘cool roofs’ and ‘cool pavements,’ reduce heat absorption. Incorporating green spaces and shade structures into city layouts enhances resilience to heat stress.
5. Community engagement is crucial for heat disaster management. Supporting neighborhood efforts, like checking on elderly residents during heat waves, boosts resilience. Providing resources such as water, cooling devices, and heat safety info improves preparedness. Encouraging residents to share ‘heat hero’ stories can boost engagement and build a shared identity, turning guidelines into inspiring actions. Training programs on recognizing heat illnesses and administering first aid enable quick emergency responses.
6. Embedding heat-wave management in wider climate adaptation is vital. Governments and planners should develop detailed heat action plans that specify roles, resource allocation, and resilience strategies. Strong policies and governance sustain scalable mitigation efforts. Cross-sector collaboration among health, urban planning, disaster management, and environmental agencies enhances response effectiveness.
