Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
1
Is any of this happening now?
Call 911
Call emergency services for confusion, unusual behaviour, severe loss of coordination, seizure, collapse, or unconsciousness during or after heat exposure.
These are signs of possible heat stroke.
Emergency help is also appropriate for breathing difficulty, chest pain, signs of shock, or a person who is too drowsy to drink safely.
Other emergency signs, for anyone
Someone who is struggling to breathe, gasping, choking, or cannot get words out
Someone who has chest pain, tightness or pressure lasting more than a few minutes
Someone who has sudden weakness or drooping on one side of the face or body, slurred speech, or sudden confusion
Someone who is unconscious, or cannot be woken
Someone who is bleeding heavily and it will not stop with firm pressure
Someone who has had a seizure that will not stop, or does not wake up afterwards
Someone who has lips or skin that look pale, blue, grey or blotchy
Someone who you believe has taken an overdose or swallowed something poisonous
2
Is any of this happening?
Be seen today
Start cooling immediately rather than waiting for help to arrive.
Seek prompt medical advice for suspected heat exhaustion when:
Symptoms are getting worse despite rest and cooling
Vomiting prevents fluid intake
Fainting is prolonged or happens repeatedly
Symptoms do not clearly improve within about an hour
Urine becomes very dark, or there is severe muscle pain or weakness
The affected person has significant heart, kidney, or other medical problems
3
Does any of this apply?
Book an appointment
Routine follow-up is reasonable after recovery if episodes keep happening, symptoms linger, or you want to review medicines and plans for future heat exposure.
Anyone discharged after heat stroke should attend the follow-up arranged by the hospital.
Every sign above is quoted from the sofidex article on Heat illness. If you are not sure, err upward — it is always reasonable to be checked.