What are the first signs of heat stroke or exhaustion?

Lethargy, headache. Lethargy, confusion, headaches. Facial flushing or turning pale depending on the hydration status. For heat exhaustion, thirst is the very first warning sign which is often ignored.
Fatigue, dizziness. Fatigue, dizziness, slow motion, imbalance, confusion, fever. The problem is dehydration and well as overheating. Get them to drink more (with electrolytes), get out of the sun, and lie down until recovered.

Related Questions

What's the difference between heat stroke and exhaustion?

Bad and Worse. Heat exhaustion refers to a situation where the body is overheated and there may be nausea and muscle cramps. There is profuse sweating and dehydration can result. If the process continues, then the body temp can increase to 106f with vascular collapse. This is heat stroke which is a medical emergency which can be fatal if not aggressively treated with IV fluids and cooling of the body. Read more...

How do doctors determine if it's heat stroke or heat exhaustion?

Severity. Heat stroke is a life threatening condition. Here is a link to an article you may find useful: http://www.Emedicinehealth.Com/heat_exhaustion_and_heat_stroke/article_em.Htm. Read more...
Change in symptoms. What is the difference between heat stroke and heat exhaustion they are on the same track. This often occurs when one starts out behind in their overall body fluid balance. But it could occur if anyone at any time with the right circumstances. Generally one has spent time in the hot sun or in a very hot environment while not keeping up with their water intake. Many times already starting out partially dehydrated. What happens next is a continuum of symptoms. It might start with fatigue, headache, weakness, dizziness, or even fainting. Other symptoms could include nausea and vomiting infusion, excessive thirst, muscle cramping and aching, a slow or weakening heartbeat. The patient may also become drenched in sweat. If the above patient is untreated and the symptoms are unrecognized the progression of the symptoms would go from what's described above (heat exhaustion) to what is known as a heat stroke. So to simply put it a heat stroke would generally be a continuation and worsening of the symptoms described above. By the time a person has a heat stroke they have often gone from profusely sweating to not sweating it all, from a slow and weak heart rate to a very rapid heart rate, from a normal temperature to a very elevated temperature such as 104 -106°F. The patient is generally going to be very confused as they can also be with heat exhaustion. The patient may also have what we refer to as delirium to go along with their confusion and many times though even have a seizure. This is clearly a medical emergency and no time should be wasted in getting that person to the emergency room. Read more...