Drivers Warned to Clear Vehicles Ahead of 30C Heatwave
Motorists across the UK are being urged to remove everyday items from their parked cars as temperatures are forecast to climb to 30C in the coming days. Stationary vehicles can heat up rapidly, subjecting anything left inside to extreme conditions that may render some products unsafe or ineffective.
According to the latest Met Office forecasts, temperatures will rise progressively, with southern England potentially reaching 30C by Wednesday. Some locations in the south and southeast could hit 33C on Wednesday and 34C on Thursday. The Met Office has also warned of a "long-lasting UK marine heatwave" that is "likely to reach extreme levels" this week, describing it as "the third and most intense marine heatwave we have seen this year."
Common Items That Become Dangerous in Hot Cars
Many motorists routinely store items in door pockets, the boot, and glove compartments, including medicines, aerosol cans, fizzy drinks, mobile phones, and battery-powered devices. These products can degrade when exposed to elevated temperatures, with medications being a particularly notable example.
Official guidance on hot weather warns that small, enclosed spaces such as parked cars can heat up remarkably fast. It also advises that babies, children, elderly people, and pets should never be left unsupervised in vehicles or other confined spaces.
Why Medication Must Be Removed
Understanding how heat affects medication is crucial for wellbeing. If medicines get too warm, they may not work properly, which can be extremely dangerous. Rhysa Phommachanh, Health Specialist at Landys Chemist, revealed eight common medications affected during the heatwave:
- Insulin: Can become less effective at high temperatures, as heat degrades it and reduces its ability to control blood sugar levels.
- EpiPens (adrenaline auto-injectors): Can become less stable if stored above 25°C, potentially reducing dose reliability in a life-threatening allergic reaction.
- Inhalers (asthma medication): High temperatures can compromise asthma inhalers because pressure fluctuations within the canister may affect medication dispensing, undermining dosing precision.
- Diuretics (water tablets): May increase urine production and fluid loss, accelerating dehydration in warm conditions and making it harder for the body to maintain temperature balance.
- Antihistamines: Can have a desiccating effect and may inhibit perspiration, restricting the body's capacity to regulate temperature efficiently.
- Antidepressants: Certain antidepressants can interfere with the brain's ability to control body temperature and sweating, increasing the likelihood of overheating or heat exhaustion.
- Antibiotics: Some antibiotics can cause photosensitivity, making skin react more intensely to UV rays and increasing sunburn risk.
- Acne treatments: Retinoids can thin or sensitise the outer layer of skin, rendering it more vulnerable to UV damage and sunburn.
Phommachanh said: "Most medications should be stored in a cool, dry place. Exposing them to high temperatures in parked cars, direct sunlight, or humid bathrooms can cause them to degrade and fail to work properly. Always check your patient information leaflet for specific storage instructions, stay well hydrated, apply high-factor sunscreen, and speak to a pharmacist if your medicine changes colour, smell, or texture."
Most medications require temperatures below 25°C or refrigeration. A statement from automotive retail group Dick Lovett's website reads: "If they aren't stored at the right temperature, medicine can lose its effectiveness, break down chemically, and even become dangerous. EpiPens, for example, can misfire or fail to deliver a full dose if exposed to heat. As such, always carry your medications with you, ideally in a small insulated pouch, and never leave them in a parked car."
Other Items to Remove From Your Car
Aerosol items, including deodorants, hairspray, and similar sprays, should be removed as pressure can accumulate dangerously in warm conditions. Gadgets such as mobile phones and portable chargers containing lithium-ion batteries present significant hazards in excessive heat, potentially harming the batteries and heightening fire risk should one malfunction.
Vaping equipment and e-liquids should be stored away from heat and direct sunlight, as rechargeable batteries and liquids can be severely impacted by elevated temperatures. Carbonated drinks can also pose difficulties, as heat causes contents to expand, leading to cans or bottles bursting or spraying when opened. Sun cream is equally vulnerable; prolonged exposure can alter its texture and cause it to leak, meaning you may not receive the required level of protection. When collecting weekly groceries, particularly chilled or perishable goods, a sweltering vehicle can rapidly push food temperatures to hazardous levels.
