Millions of people across the UK are on medications which could be affected by the heat (Picture: Shutterstock / i viewfinder)How does the hot weather impact medicine? The Medicines and Healthcare products Regulatory Agency (MHRA) has issued a statement reminding people that hot weather can affect how well medicines work. It reads: ‘Most medicines need to be stored at temperatures below 25C. One popular medication that you might not realise this could be an issue for is the contraceptive pill. Around 76 per cent of women of reproductive age in the UK use some form of contraception, and more than 3million are thought to be taking a contraceptive pill.