HighlightsWe report the rational design of structure-switching DNA aptamers for potassium.The shift between non-binding and binding-competent states was determined experimentally.The stability of the non-binding state was estimated computationally.A linear free energy relationship between these values was established.

Our identification of common EMS dispatch complaints, mechanisms of injury, and primary assessments can be used in the education of staff and preparation of facilities for medical emergencies and injuries where children spend time.