The National Weather Service put an unusual instruction in its heat products for Missouri this week. Alongside the standard advice about fluids and air conditioning, forecasters told residents to "know the signs and symptoms of heat exhaustion and heat stroke."
That is worth taking literally, because the two conditions can start the same way and only one of them is survivable without emergency care. Heat exhaustion usually responds to cooling and rest. Heat stroke kills people who are given a glass of water and told to sit down.
