One of our closest friends has a serve nut allergy and a very dear family friend has environmental allergies. How do we ensure that guests do not eat nuts before attending the reception, where a hand shake could send our friend to the hospital? With the environmental it's more an issue with guests wearing perfume or cologne, which, aside from the family friend's issue, my father has respiratory issues with and I get bad headaches from.
Any suggestions on how to address these issues?