Heat illness: on-site diagnosis and cooling.

Heatstroke is a true sports emergency. By recognizing the key signs and symptoms a core body temperature above 40.5 degrees C and mental status changes on-site physicians can begin urgent management of heatstroke. Cooling must begin immediately; ice water immersion is best if practical, but other measures can be effective. Other conditions common in the heat, like 'heat cramps,' 'heat exhaustion,' and 'heat syncope,' are less serious and generally require less drastic measures. Cramps typically respond to sodium replacement, and heat exhaustion and syncope require rest and possibly cooling and rehydration.