Some medicines can make it harder for the body to cope with extreme heat, potentially increasing the risk of dehydration, overheating and other heat-related problems.

During Europe’s June heatwave, 28-year-old Ileana Okumus struggled with the heat in Brussels despite having previously experienced summers with temperatures reaching 40C (104F).

Living in a top-floor apartment without air conditioning, Okumus said she began sweating heavily as soon as she went outside and found it difficult to cool down even after returning indoors. On one particularly hot day, the temperature inside her apartment reached 34C (93F), and she slept for around 18 hours.

Okumus eventually connected her symptoms to medicines she had started taking two years earlier for depression and anxiety. After seeing social media posts from people describing similar experiences, she began to suspect that her medication could be affecting how her body responded to high temperatures.

Certain medicines can interfere with sweating, blood pressure, hydration or the body’s ability to regulate temperature. These effects can become especially important during heatwaves, when prolonged exposure to high temperatures already places additional stress on the body.

The experience highlights why people taking regular medication may need to take extra precautions during periods of extreme heat and discuss potential heat-related side effects with their healthcare professionals.