How does an import/export business expose itself to foreign exchange risk?

Could you elaborate on how an import/export business becomes vulnerable to foreign exchange risk? Are there specific transactions or operations within the business model that inherently expose it to such risks? Additionally, how does the variability in exchange rates directly impact the profitability and financial stability of such a business? Lastly, are there any strategies or mechanisms that these businesses can adopt to mitigate or hedge against foreign exchange risks?