They could be symptoms of any of the major heat illnesses described below. Heat Cramps Salts can be lost in the sweat while running in the heat. If they are not replenished properly, muscle pain and cramps can occur. The body temperature does not become elevated. Prevention can come from heat acclimatization, ingestion of large amounts of water and by increasing the daily salt intake several days before the heat stress.
Treatment is rest in a cool environment and replacement of lost salts.
Heat Exhaustion Poor circulatory response to heat and reduction of blood volume due to increased sweating can lead to symptoms of general weakness, dizziness and nausea. The skin is usually cool and pale, but the person is probably still sweating. Exercise must be stopped. Treat by rest in a cool environment, ingestion of cool liquids and cooling the body externally with water or ice. When the body's temperature regulating system fails, excessively high body temperature and heat stroke can result.