Conditions Back ConditionsDrugs & Supplements Back Drugs & SupplementsWell-Being Back Well-BeingMore Back More Privacy & More Subscribe Log In Search Subscribe Understanding Heat-Related Illness -- SymptomsWritten by Medically Reviewed by Carol DerSarkissian, MD on September 25, 20241 min readWhat Are the Symptoms of Heat-Related Illnesses?Heat cramp symptoms can include:Severe, sometimes disabling, that typically begin suddenly in the hands, , or feetHard, tense muscles symptoms can include:HeadacheExcessive thirstMuscle aches and crampsConfusion or anxietyDrenching sweats, often accompanied by cold, clammy or a sensation of prickly skinSlowed or weakened heartbeatAgitationHeat exhaustion requires immediate attention.Heat can include:Increased (103 degrees F or higher)Dizziness or Hot, flushed, Rapid Dry skinProfound Shortness of breathDecreased urination or stoolConfusion, delirium, or loss of consciousnessConvulsions can occur suddenly, without any symptoms of heat exhaustion. If a person is experiencing any symptoms of heat exhaustion or , GET MEDICAL CARE IMMEDIATELY. Any delay could be fatal.SourcesUpdate HistorySharePrintSOURCES: The American Red Cross. American Academy of Family Physicians.SharePrintMore on First Aid Recommended FEATURED Top doctors in , Find more top doctors on Search Related LinksPoliciesAboutFor Advertisers © 2005 - 2025 WebMD LLC, an company. All rights reserved. WebMD does not provide medical advice, diagnosis or treatment. , Heat stroke is the most severe form of heat illness, with primary symptoms that include confusion, altered mental status and a very high core body temperature above 104 degrees Fahrenheit (40 degrees Celsius). Heat exhaustion is less dangerous, but can present with muscle cramps, headaches, dizziness, weakness, fatigue, nausea and vomiting., Heat exhaustion occurs when your body loses excess amounts of water and salt, typically from sweating. On the other hand, heat stroke is a serious medical emergency that occurs when your.