Which of the following is a sign or symptom of heat exhaustion that requires you to call EMS/9-1-1?

In cases of heat exhaustion, a critical sign or symptom that indicates the need to call emergency medical services is confusion. Confusion can signify a serious progression from heat exhaustion to heat stroke, which is a medical emergency. When an individual becomes confused, it may indicate their body is struggling to regulate temperature and is experiencing significant physiological distress. This level of impairment suggests that immediate medical evaluation and intervention are necessary to prevent further complications.

While anxiety, excessive sweating, and headache can be associated with heat exhaustion, they do not inherently signal an immediate risk to life or health, as confusion does. Anxiety may arise in response to heat stress but doesn't typically warrant emergency intervention by itself. Excessive sweating is a common response of the body to help cool down and might not necessitate emergency assistance unless accompanied by other severe symptoms. A headache can result from dehydration or heat but is also not a definitive indicator for calling for emergency help.