Climate change is contributing to more frequent, severe, and longer heat waves during the summer months.

The definition of a heatwave in Glasgow is when records show a period of at least three consecutive days with maximum temperatures above 25C, however we know that impacts from heat can be felt for periods shorter than this.

Extreme heat events in cities can cause mortality spikes of up to 14%, as well as lower workforce productivity and damage infrastructure such as roads and rail lines.

If there is sustained exposure to extreme heat, this can lead to heat exhaustion, severe dehydration, and heat stroke for residents. There are significant health risks arising from extreme daily maximum temperatures, high overnight temperatures, high humidity and air pollution, as well as a prolonged duration of a heatwave.

We can help to increase awareness of the symptoms of heat stress, including headaches, vomiting, dizziness and low blood pressure. Heat waves also exacerbate existing health issues, including cardiovascular and respiratory disease. Heat waves are associated with increased hospital admissions, psychological stress, aggressive behaviour as well as excess mortality.

People with underlying medical conditions, older people and young children are more sensitive to extreme heat. In addition, pregnant women and women with babies are more affected, as breastfeeding is extremely dehydrating. Outdoor workers, who have high exposure and may have jobs requiring physical exertion are also more vulnerable to heat stress.

We need to share information on which areas of the city, and which groups of the population, are most at risk during heat waves. The vulnerability of residents depends on their exposure and sensitivity to extreme heat, and people’s ability to adapt.

Through developing the city’s work on a heat vulnerability assessment, we can deliver activities to reduce urban heat which support people’s health and the city’s economy. There are specific benefits through creation of jobs and improved local neighbourhood environments. 

Initiatives to reduce urban heat create business opportunities and employment, for example installing green roofs and green walls. We can respond to extreme heat by supporting urban woodland, increasing tree planting and more green spaces which can make impressive contributions to lowering urban heat.

Extreme heat days can put considerable strain on electricity grids as demand for air conditioning increases. Investment in energy efficiency to reduce energy costs for commercial buildings and the housing sector can lower demand for cooling.  

Heat waves are taking a disproportional toll on lower income communities in neighbourhoods with less tree cover. Concrete and asphalt roads, and other built materials readily absorb, store and release heat, raising city temperatures, creating a phenomenon called the urban heat island.

Local government is already deploying strategies for heat mitigation to reduce urban heat islands, but more work is needed to respond to heatwaves. We can support council services to reduce the inequitable distribution of heat risks, and take further action to help protect vulnerable families, friends and neighbours from heat stress.

Local councils can support the development of heatwave plans within their planning framework and provide additional support to local communities during heatwaves.