As South African transport operators prepare for another demanding summer, Babcock's DAF Trucks business highlights the importance of vehicle maintenance, driver wellbeing and intelligent fleet management in maintaining safety, reliability and uptime during periods of extreme heat.
Prolonged high temperatures present significant challenges for commercial vehicle operators. From increased demands on cooling systems and braking performance to tyre wear, fuel consumption and driver fatigue, extreme heat can place additional pressure on vehicles already operating under demanding conditions.
In a recent FleetWatch special report examining the potential impact of extreme El Niño conditions on the trucking industry, Babcock's DAF Trucks business shared practical insights into how fleet operators can prepare their vehicles and drivers for sustained high temperatures.
According to Marius Barnard, Managing Director of DAF Trucks South Africa, while modern trucks are engineered to withstand demanding operating environments, technology alone is not enough. Preventative maintenance, informed driving practices and proactive fleet management remain essential to reliable transport operations.
Engineered for demanding African conditions
DAF trucks are developed and tested for operation in some of the world's most challenging environments, including regions where ambient temperatures regularly exceed 40°C. Their cooling systems, engine management technology, driveline components and climate-control systems are designed to maintain reliable performance under prolonged heat exposure.
DAF's powerful MX Engine Brake also plays an important role in thermal management. By dissipating braking energy through the exhaust system, it reduces the demands placed on conventional braking systems and hydrodynamic retarders, helping to manage heat during demanding operating conditions.
Advanced electronic engine management and sensor systems continuously monitor vehicle performance, enabling drivers and operators to identify potential issues before they develop into more serious problems. However, as operating conditions become increasingly demanding, even well-engineered vehicles depend on correct maintenance and operation.
Preventative maintenance: the first line of defence
Extreme heat places particular strain on engine cooling systems, tyres, brakes, batteries, air-conditioning systems and electronic components. Babcock recommends that fleet operators prioritise comprehensive vehicle inspections ahead of the summer months, with particular attention to:
- Cooling systems: Inspect radiators, intercoolers, cooling fans, hoses, clamps and coolant levels. Keep radiators clean and free of obstructions.
- Coolant condition: Use only DAF-approved coolant and follow recommended replacement intervals. Mixing incompatible coolants or using incorrect specifications can compromise cooling performance.
- Radiator caps: Check their integrity and replace them annually in accordance with DAF's recommendations.
- Tyres: Inspect tyre condition, inflation pressures and wheel assemblies regularly, particularly on long-distance routes.
- Braking systems: Check components for wear and signs of overheating, especially on vehicles operating with heavy loads or over mountainous terrain.
- Batteries and air-conditioning: Ensure charging systems and cab cooling equipment are functioning correctly.
Small maintenance oversights can have significant consequences when ambient temperatures rise. A partially blocked radiator, deteriorating hose or minor coolant leak may have little immediate impact under normal conditions but can become a serious reliability concern during prolonged heat. DAF advises operators to follow prescribed service schedules, with additional inspections where particularly severe operating conditions warrant them.
Tyre and braking safety in high temperatures
Road surface temperatures can be considerably higher than the surrounding air temperature, increasing the heat absorbed by tyres during operation. High tyre temperatures can accelerate wear and contribute to casing fatigue, particularly when inflation pressures are incorrect. Importantly, operators should not arbitrarily reduce tyre pressures to compensate for hot weather. Under-inflation can increase rolling resistance, heat build-up and tyre wear. The correct approach is to maintain manufacturer-recommended pressures and conduct regular inspections, preferably when tyres are cool.
Braking performance also requires careful management. On long descents, excessive reliance on service brakes can result in overheating and brake fade, reducing braking effectiveness. DAF recommends that drivers use engine braking systems and retarders appropriately, select the correct gear before descending and avoid continuous application of the service brakes. DAF vehicles are equipped with Downhill Speed Control (DSC), which helps regulate vehicle speed on descents by coordinating the available braking systems when activated. Effective driver familiarisation and training are essential to ensuring these technologies are used correctly.
Smarter fleet management through vehicle data
Modern fleet management technology provides another important layer of protection against heat-related breakdowns. Babcock's DAF Trucks business offers Executrax, its telematics system, which enables fleet operators to monitor vehicle performance and operating behaviour remotely. Relevant information includes engine temperature, fuel consumption, idling time, driver behaviour, maintenance alerts and fault codes. By identifying abnormal operating conditions early, fleet managers can intervene before minor issues develop into costly breakdowns.
Telematics also supports more efficient fleet operations. Excessive idling, harsh acceleration, congestion and increased air-conditioning demand can all affect fuel consumption during hot weather. Monitoring these factors allows operators to identify opportunities to improve driving efficiency, reduce unnecessary vehicle stress and better manage operating costs.
Route planning can also make a difference. Where operationally practical, avoiding peak congestion and scheduling certain journeys during cooler periods can reduce thermal stress on vehicles while improving driver comfort.
Driver wellbeing is a safety priority
Extreme heat affects more than vehicle performance. It can also compromise driver concentration, alertness and physical wellbeing. Long hours behind the wheel, high cabin temperatures and inadequate hydration increase the risk of fatigue and heat-related illness. Babcock recommends that transport operators place particular emphasis on driver wellbeing during the summer months. Drivers should remain adequately hydrated, take regular breaks, maintain healthy sleep routines and ensure cab air-conditioning systems are functioning correctly.
Warning signs of heat stress include dizziness, headaches, excessive sweating, fatigue, muscle cramps, nausea and reduced concentration. Drivers experiencing these symptoms should stop, cool down and seek medical attention where necessary.
Cab comfort is therefore an important operational consideration, rather than simply a convenience. DAF truck cabs are designed with driver comfort, ergonomics and safety in mind, while effective air-conditioning helps drivers remain alert during long journeys.
Driver training also plays an important role. DAF Trucks South Africa provides vehicle familiarisation and driver training programmes covering efficient vehicle operation, correct use of driver assistance systems and aspects of driver wellbeing.
Additional precautions for refrigerated transport
For temperature-controlled transport operators, extreme heat creates further challenges. Refrigeration equipment must work harder to maintain the required cargo temperatures, potentially increasing fuel consumption and component wear. Operators should pay particular attention to refrigeration unit servicing, temperature monitoring, door seals and loading practices. Minimising unnecessary door openings and maintaining accurate temperature records can help protect temperature-sensitive cargo and reduce the risk of disruption. More frequent inspections may also be beneficial during sustained periods of extreme heat.
Protecting uptime through preparation
For transport operators, the consequences of heat-related failures extend beyond the cost of repairs. Unplanned downtime can disrupt delivery schedules, affect customer commitments and increase overall operating costs. Babcock advocates a proactive approach built around three priorities: maintaining critical vehicle systems, protecting driver health and using vehicle data to identify potential problems early.
Through DAF's advanced vehicle technology, preventative maintenance programmes, driver training and aftermarket support, Babcock helps customers maintain reliable fleet operations in demanding South African conditions. As temperatures rise, the message for fleet operators is clear: preparation, preventative maintenance and informed vehicle operation remain the most effective ways to protect safety, efficiency and uptime.
Based on technical insights provided by Babcock's DAF Trucks business for FleetWatch's special report, “Super El Niño – Can your trucks take the heat?”, Volume 93, 2026.
