Which illness can you contract from leaving a bottle of olive oil infused with garlic or herbs unrefrigerated?

Leaving a bottle of olive oil infused with garlic or herbs unrefrigerated can lead to the growth of Clostridium botulinum, the bacteria that causes botulism. This is particularly risky if the infusion is not properly acidified, as the anaerobic environment can promote the bacteria's growth. Symptoms of botulism can be severe and include muscle weakness, double vision, and difficulty swallowing. It's essential to refrigerate such infusions and consume them within a short period to mitigate this risk.