Heatwaves: adapting to climate change Contents

4Productivity during heatwaves


Public Transport

104.The Adaptation Sub-Committee notes that all forms of transport are affected by high temperatures. In particular, railway tracks are vulnerable to buckling and road surfaces can soften, rut and even melt under high temperatures. Train carriages, underground carriages and buses are vulnerable to overheating. The 2013 National Adaptation Programme recognises “there are potential economic consequences from local transport failure with knock on implications for other sectors”.155

105.Network Rail maintains and develops Britain’s rail infrastructure. They outlined the effects of heatwaves in their written evidence:

Hot weather and periods of prolonged high temperatures can have a significant potential impact on the performance and safety of the railway… The temperature of the steel rails in direct sunlight can be more than 20 degrees above ambient air temperature. This means that, during hot weather the rails can expand and the build-up of forces can cause the track to distort laterally or “buckle”.156

106.Chief Track and Lineside Engineer at Network Rail, John Edgley told us that the number of service-affecting failures doubles during a period of hot weather.157 Buckling can delay services as well as result in their failure. When temperatures are high, trains are often run at a restricted speed to lower the force on the track and reduce the risk of buckling. During the period of very warm weather in late June 2018, train services in Northern Ireland were restricted and track near Carlisle buckled. Buckling events due to hot weather are expected to be four to five times more frequent by the 2050s. The Adaptation Sub-Committee’s state that during the 2003 heatwave “137 rail buckles cost £2.5 million in delays and repairs… By the 2080s, the annual cost of buckling and heat-related delays under a high climate change scenario could increase eightfold.”158

107.Network Rail also outlined that electrical equipment can fail.159 Sam Longman, Policy Manager for Environment at TfL explained the effects of this on the London Underground:

… in transport, one of the things that concerns us is the interdependencies… One of the problems we see with transport is fluctuations in heat, so that when we get the first hot day, electronic equipment goes down, but what is the knock-on impact of that? Do you end up with signal failures, or people being trapped in tunnels, for example, and overheating as a result?160

108.Network Rail told us they were not aware of any studies to quantify the economic consequences of significant transport disruption. However, they provided an example of the impact an extended period of line closure in the context of flooding had on the local economy. The closure of the Dawlish section of track in Devon between February and April 2014 was estimated to cost up to £1.2 billion to the local economy. Network Rail outlined the impact:

Tourism spending over the Spring period was reportedly significantly down compared to the same period the previous year and the fishing industry experienced a significant reduction in sales during this period compared to the projected spend at that time of the year.161

Thermal comfort

109.The Tyndall Centre for Climate Change outlines that heatwaves cause thermal discomfort on the London Underground. Deep tube lines such as the Central and Bakerloo lined can be 10°C hotter than surface temperatures, with in-car conditions of around 30°C in summer.162 Sam Longman from TfL explained that overheating on public transport can also result in increased demand for air conditioning. Mechanical cooling systems on buses put pressure on engines to work harder, therefore adding to air pollution and potentially exacerbating the urban heat island effect.163

110.Overheating bring risks to public health. During the 2015 heatwave, Public Health England advised employers to let their staff travel at less busy times. The Adaptation Sub-Committee also suggest that overheated transport could lead to a loss of work days as heat-vulnerable individuals, such as older people or pregnant women may not be able to travel.164

111.Kathryn Brown, Head of Adaptation at the Committee on Climate Change noted there is a lack of evidence about the heatwave resilience of public transport beyond London.165 We did not receive any evidence from a local authority outside London on the resilience of their transport systems. Transport for London’s ‘Cooling the Tube’ programme involves predicting future tunnel temperatures and installing effective mitigation measures such as mechanical cooling:

At Transport for London, we have a cooling hierarchy. First, we try to recycle any wasted energy, through, say, regenerative braking, instead of letting that escape as heat. We try to make the whole system as efficient as possible, such as by introducing coasting instead of active braking. We try to recover wasted heat. We have an example in Bunhill where we try to export waste heat into a heat network.166

112.There are a range of risks to public transport from heatwaves including, service disruption, health impacts and potential economic losses. Protecting health could lead to increased mechanical cooling which could in turn amplify the urban heat island effect. The Government should coordinate a study of vulnerability to heat-health risks on transport and how this contributes to economic loss during heatwaves. The study should consider how the increased demand for mechanical cooling can be offset through recovering and utilising waste heat.


113.Hot temperatures can cause road surfaces to soften, rut and even melt. In the 2006 heatwave, there was damage to road surfaces across the country, from Cornwall to Cumbria. A study of the 2003 heatwave found that road maintenance cost £40.6 million.167 Certain types of road surface are more vulnerable to melting. Highways England, the government company responsible for the strategic road network, now surfaces roads with Thin Surfacing Course Systems which are resilient to high temperatures. However, hot rolled asphalt bituminous surfacing and concrete still make up approximately 50% of the strategic road network. These surfaces tend to rut under the action of traffic during very hot weather. Mike Wilson, Chief Highways Engineer at Highways England explained the impact of the 1995 heatwave on these surfaces:

We had a very hot summer in 1995, where we saw a combination of very hot weather and a change in tyres in HGVs. They moved from double tyres on the back of trailers to what they call super-single tyres—a much greater concentration, and we saw an increase in the amount of rutting particularly on the strategic road network, particularly uphill.168

During the very warm period of late June 2018 some bitumen roads in Cumbria began to melt, leading the local council to grit surfaces. A section of the A543 in Conwy county, Wales was closed in both directions because the road surface melted.

114.Highways England’s Climate Change Adaptation Strategy and Framework identifies extreme summer temperatures as of high importance to Highways England users.169 Mike Wilson said that the issue of people being trapped in their vehicles due to congestion caused by heat was an area of consideration for Highways England:

We have well-established incident management arrangements to help people avoid the back of the queue and to get people past the incident so that they can continue with their journey and provide for their own welfare. In extreme circumstances, we have capability through local resilience forums for them to provide welfare on to the network.170

115.We did not receive written evidence from any local authority or local government organisation regarding the heat resilience of local roads, despite the significant economic cost of heatwaves. The cost of repairs during the 2003 heatwave was estimated at £3.6m in Oxfordshire alone.171 The 2013 National Adaptation Programme set an Action for the Environment Agency Climate Ready service to “support the Local Government Association’s Climate Local initiative to signpost advice, tools and examples that help councils improve the resilience of local transport infrastructure.”172 However, in 2015/16 Climate Local and Climate Ready had their funding withdrawn. Lord Gardiner told us he would seek further clarification of local road resilience:

One of the things I want to take back is this sort of information to say that local authorities that have a lot of minor roads that need to be resilient to extreme weather and heatwaves, is the information and new techniques used on the minor roads system and what are the cost implications? I am afraid I do not know about the cost implications of it, but clearly in terms of readiness and preparedness, we need to be ensuring that the road network and the rail network can function and accommodate increasing temperatures, whatever that degree will be.173

116.Only 50% of England’s strategic road network is surfaced with the most heat resilient material. During the hot weather in June 2018, roads across the UK, from Cumbria to the south were at risk of melting, and the A543 in Wales had to be closed. Highways England should ensure that resurfacing of roads in at-risk areas is a priority, as heatwaves have become increasingly common. Very few car journeys start and end on the strategic road network, however the heat resilience of local roads is unclear, and support systems for local authorities no longer exist. Previous UK heatwaves led to very costly road repairs, the costs of which will fall on local authorities. The Department for Environment, Food and Rural Affairs should review the capacity of local authorities to undertake adaptation focused maintenance of local roads.

Economic productivity

117.The Adaptation Sub-Committee’s Climate Change Risk Assessment Evidence Report notes that heatwaves bring risks to productivity, but also some benefits for the economy. The main risks include decreased workplace productivity due to overheating, loss of work days due to transport failures, significant costs to the healthcare sector and high maintenance costs to roads and public transport. Heatwaves can bring some economic opportunities through increased tourism and greater demand for services near outdoor leisure centres and beaches. The Welsh Government has identified tourism as a key sector for growth potential due to warmer temperatures. However, Head of Adaptation, Kathryn Brown noted that any study of the economic consequences of heatwaves concluded that there was a more significant cost to the economy than benefit.174 A study of the 2003 heatwave found that costs to the health sector were approximately £41 million.175

118.Heatwaves result in decreased workplace productivity. The Adaptation Sub-Committee suggest that overheating work environments can lead to heat stress, particularly for workers engaged in heavy outdoor manual labour or employees working in offices built in the 1960s and 1970s as these tend to have poor ventilation systems. A study on the impact of overheating on employee productivity using data from the Inter-Departmental Business Register,176 quantified that in 2010, approximately five million staff days were lost due to overheating above 26°C. Based on an average staff cost of £150 per day, this resulted in an economic loss of £770 million.177 Given that extreme temperature events in Europe are now 10 times more likely than they were in the early 2000s, similar losses will occur more frequently. The Adaptation Sub-Committee recommend that businesses produce continuity plans to avoid significant economic losses during an extreme weather event. Although the National Adaptation Programme set an action for the Cabinet Office to create a ‘business continuity for dummies guide’, the Adaptation Sub-Committee found that significant number of businesses still do not have business continuity plans in place, and that they are often developed only after an organisation has been impacted by extreme weather.178 Smaller businesses are less likely to have business continuity plans in place.

119.Employers must provide a “reasonable” workplace temperature under section 7 of the Workplace (Health, Safety and Welfare) Regulations 1992.179 The Chartered Institute of Building Services Engineers (CIBSE) has established thermal comfort guidelines for workplaces. They note that indoor temperatures of over 28°C for long periods are likely to result in reduced productivity, and that steps such as relaxing the dress code and encouraging flexible working hours should be taken.180 Those working in roles that involve heavy manual labour are particularly vulnerable. The Adaptation Sub-Committee found that the 2003 heatwave is estimated to have resulted in a loss of manufacturing output in the UK of £400 - £500 million.181

120.The Health and Safety Executive has issued an Approved Code of Practice on providing reasonable workplace temperatures. They suggest that the minimum temperature in a workplace should be 16°C, but note that a “meaningful figure cannot be given at the upper end of the scale.”182 In 2017, the Trades Union Congress called on employers to temporarily relax workplace dress codes to enable staff to work comfortably through the heatwave.183 However, the design of office buildings can make it difficult to mitigate the high internal gains during a heatwave.

121.Productivity in schools is also affected by heatwaves. Schools are vulnerable during heatwaves. We note that heat health alerts notify, among others, school nurses about the risks of heatwaves, but in the last 8 years the number of school nurses has been cut by 700.184 Children cannot control their body temperature as efficiently as adults during hot weather because they do not sweat as much and are therefore at an increased risk of ill health. A survey of 135 teachers conducted for this inquiry found that 100% of respondents felt high temperatures affected the productivity of students and 52% felt productivity was affected “significantly”. However, only 7.4% of teachers had been able to send children home during periods of uncomfortably hot weather. Many respondents called for more air conditioning in schools, and improved building design. We heard anecdotally that some schools were inflexible on their uniform policies and did not allow pupils to take their blazers off.

122.Heatwaves can result in overheating workplaces and lower employee productivity. In 2010, approximately five million staff days were lost due to overheating above 26°C resulting in economic losses of £770 million. Given that extreme temperature events in Europe are now 10 times more likely than they were in the early 2000s, similar losses will occur more frequently. However, some businesses, particularly smaller businesses, do not have business continuity plans in place. The Government should make businesses aware of the developing threat of heatwaves and the economic consequences. Public Health England should also issue formal guidance to employers to relax dress codes and allow flexible working when heatwave alerts are issued. The Government should consult on introducing maximum workplace temperatures, especially for work that involves significant physical effort. Procurement rules should be updated so that schools and the NHS do not spend public money on infrastructure which is not resilient to heatwaves. The Department for Education should issue guidance for head teachers about safe temperatures in schools and relaxing the school uniform policy as appropriate during hot weather.

156 Network Rail (HTW0027)

161 Network Rail (HTW0032)

162 Tyndall Centre for Climate Change Research (HTW0012)

167 Hunt, A 2007, ‘Study on the economic effects of the 2003 heat wave on transport’ Paper presented at Institute of Asphalt Technology National Conference, Telford, UK United Kingdom, 24/05/07

169 Highways England (HTW0024)

175 Hunt, A 2007, ‘Study on the economic effects of the 2003 heat wave on transport’ Paper presented at Institute of Asphalt Technology National Conference, Telford, UK United Kingdom, 24/05/07,

Published: 26 July 2018