Serious bug bites
Not uncommonly, people have a serious systemic (beyond local) reaction to bug bites, particularly bees, wasps, yellowjackets.
These may cause swelling in the mouth or throat, hives
...An anaphylactic reaction. Any systemic reax must be reported to doc, or if trouble breathing, treated emergently. For such potential reactions, emergency measures must be available, such as an epi-kit.