Diagnosis

It's usually apparent to doctors if you have heatstroke, but laboratory tests can confirm the diagnosis, rule out other causes for your symptoms and assess organ damage. These tests include:

• Rectal temperature to check your core body temperature. A rectal temperature is the most accurate way of determining your core body temperature and is more accurate than mouth or forehead temperatures.
• A blood test to check blood sodium or potassium and the content of gases in your blood to see if there's been damage to your central nervous system.
• A urine test to check the color of your urine, because it's usually darker if you have a heat-related condition, and to check your kidney function, which can be affected by heatstroke.
• Muscle function tests to check for serious damage to your muscle tissue (rhabdomyolysis).
• X-rays and other imaging tests to check for damage to your internal organs.