system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How does breathing in eucalyptus or menthol help unblock my nose?

I have a cold and have rubbed Vick’s ointment on my chest and it has instantly unblocked my nose, how does this occur?
gpt
They stimulate the "cold" receptors in your nose, causing the blood vessels in the area to constrict as a measure to preserve body heat. Since congestion is caused by dilated blood vessels, you experience temporary relief of those symptoms.