Final answer:
The most likely sudden illness in this scenario is anaphylaxis, a severe allergic reaction that can cause difficulty breathing and swelling of the throat.
Step-by-step explanation:
The sudden illness that you are most likely to suspect in this scenario is anaphylaxis.
Anaphylaxis is a severe allergic reaction that can occur when a person is exposed to an allergen, such as certain foods, insect stings, or medications. It can cause a rapid and severe response in the body, including difficulty breathing and swelling of the throat, which can lead to a life-threatening situation.
If the person is having trouble breathing and appears responsive, it is important to call for emergency medical assistance immediately and follow any first aid protocols for anaphylaxis, such as administering an epinephrine auto-injector if available.