“Secondhand vape inhalation”

My recommendation is to totally stop vaping or breathing vapors from other people who are vaping. Vaping can include nicotine and other irritating chemicals. Long-term concern is possibly inducing throat and neck cancer.

It depends on how long the sensation lasts, and whether or not you'll be continually exposed. If brief secondhand inhalation led to mild discomfort that ends quickly, then it's likely a small concern.

If the burning lasts and doesn't go away, gets worse, or other symptoms develop, go see your primary care provider. If at any point it causes swelling that makes it hard to breathe, or it becomes hard to breathe for any other reason, seek emergency help immediately.