Don’t let this heatwave affect your medicines: Three important tips from the MHRA

As the UK braces for another scorching day of high temperatures today, the Medicines and Healthcare products Regulatory Agency (MHRA) is reminding people that these hot conditions can affect medicines and how well they work. Hot weather changes how your body responds to medications, which could impact people managing long-term conditions – but a few simple steps can help avoid problems.

Alison Cave, Chief Safety Officer at the MHRA, said:

“Let’s face it – when there’s a heatwave, most of us are focused on getting outside and enjoying it while it lasts. But it’s easy to forget that medicines left in the heat – in cars, bags, or on sunny windowsills – might not work properly when you need them.

“Some medicines can also make you more likely to burn in the sun, feel dizzy, or get dehydrated, especially if you’re taking diuretics or have a condition like asthma, heart disease, or diabetes.

“To stay safe in the heat:

1. Store medicines somewhere cool, dry and out of direct sunlight – especially if you’re out and about
2. Know the signs of heat-related illness – stay hydrated and listen to your body
3. Take extra care in the sun if your medicine makes your skin more likely to burn

“And remember, for all medicines it’s important to read the leaflet and speak to a healthcare professional if you have any questions.” 

Read full press release

Source: MHRA, 26 May 2026