Racing a marathon in hot weather is one of the most challenging conditions a runner can face. Heat increases your heart rate, accelerates fatigue, and increases risk of heat illness. If your marathon is in a warm climate, preparation is essential.

First, acclimate to heat by doing some of your training runs in warm conditions. This helps your body adapt to running in heat and improves your thermoregulation abilities.

Second, hydration becomes even more critical in heat. You’ll sweat more, losing both water and electrolytes. Practice your race-day hydration strategy during training to ensure your gut can handle it.

Third, slow down. In hot weather, it’s important to run by effort rather than pace. A pace that feels comfortable on a cool day will feel much harder in heat. Accept that you’ll run slower and focus on effort and completion rather than time.

Fourth, use whatever cooling strategies are available: ice vests, cold water on the body, ice slurries, or shade when possible. Every bit of cooling helps in hot weather.

Finally, respect the heat. If you start to feel symptoms of heat illness—severe dizziness, nausea, cessation of sweating—stop and seek medical help. No race is worth risking your health.