Beating the Heat
Young Ju, Ph.D.
The National Oceanic and Atmospheric Administration’s summer 2025 forecast indicates that temperatures in July through September are predicted to be higher than average (1). You should be aware of the risks of competing in very hot weather and the heat safety strategies that can help you. Details on the physiological and metabolic changes that occur during heat adaptation were discussed in our Sept 2024 NWTO newsletter article.
Heat-Related Illnesses
When playing tennis in the heat, the body loses more fluids, the heart beats faster, muscles get tired quicker, and you could suffer from heat-related illnesses such as dehydration, heat cramps, heat exhaustion, and heat stroke (2). Symptoms include excessive sweating, dizziness and fatigue, nausea or headaches, rapid heartbeat, and confusion/disorientation. Some people are at greater risk than others, including people with chronic diseases (e.g., asthma or heart disease) or those 65 years of age or older. Excessive heat could cause:
Heat cramps: loss of salt and fluids from sweating could cause muscle spasms, usually in the legs or abdomen.
Heat exhaustion: heavy sweating, dizziness, nausea, headache, and weakness.
Heat stroke: the most severe form of heat-related illness, characterized by a body temperature of 104°F (40°C) or higher. It requires immediate medical attention.
Checklist for Preventing Heat-Related Illnesses
Be prepared for playing and competing in high-temperature situations by building heat endurance and practicing in the heat. Gradually build up your fitness. Heat adaptation could take a few weeks to a few months. Before and during playing:
Check the temperature and UV index.
Stay hydrated and maintain a proper diet before, during, and after matches and training. Also, check the color of urine. Pale yellow indicates proper hydration, while darker yellow could indicate dehydration.
Have a supply of ice in your cooler.
Restore electrolytes lost during intense sweating (See July 2024 NWTO article).
Wear appropriate clothing–lightweight, loose-fitting, breathable, light-colored, and UV-protective.
Use sunscreen (See May 2025 NWTO article) and wear a hat and sunglasses to protect the skin and eyes.
Use shade strategically during breaks and changeovers; if shaded areas are not available, consider using an umbrella.
Use cooling strategies such as ice towels, neck cooling, cold packs, a handheld fan, cold drinks, and ice slushies, etc.
Take frequent breaks.
Watch for any heat stress signs and symptoms: thirst, irritability, headache, goosebumps, weakness, dizziness, muscle cramps, chills, nausea and vomiting, sudden chest pain or tightness, or shortness of breath that doesn’t quickly improve. If you notice any of the listed signs, take immediate and proper action.
Summary: Stay cool and safe so you can beat the heat–and your opponent!
Dr. Young Ju is a Ph.D and Associate Professor of Human Nutrition, Foods, and Exercise at Virginia Tech.
References
National Weather Service, “Central Region Climate Outlook July 2025-September 2025” https://www.weather.gov/media/mbrfc/climate/Climate_Outlook.pdf#:~:text=Above%20normal%20temperatures%20are%20favored%20across%20the,analog%20based%20on%20sea%20surface%20temps%20(SSTs).
Center for Disease Control and Prevention. “About heat and your health”https://www.cdc.gov/heat-health/about/index.html?CDC_AA_refVal=https%3A%2F%2Fwww.cdc.gov%2Fextreme-heat%2Fabout%2Findex.html
This information is provided for your reference and you use at your own risk; you should rely on your medical professional for medical advice.
