How To Run In Hot Weather

This guide explains how to approach how to run in hot weather, including the preparation, practical steps, common mistakes, and final checks that help you finish with confidence.

30-60 min: Time needed for prep

Moderate to High Difficulty

Dehydration, Heatstroke Watch out for

Before You Start

Check first: Do not run if a severe heatwave warning is active, or if you feel unwell, dizzy, or unusually fatigued before you even start. Prioritise your safety above all else.

Step-by-Step Instructions

Quick Reference

Common Problems When You Run In Hot Weather

Dehydration

Problem: Feeling excessively thirsty, dry mouth, reduced urine output, or dark urine during or after your run. Dehydration can lead to fatigue, dizziness, and muscle cramps, significantly impacting performance and health.

Fix: The best fix is prevention through consistent hydration. Drink water steadily throughout the day, not just before your run. During the run, carry water or an electrolyte drink and sip it every 15-20 minutes. After your run, continue to rehydrate gradually over several hours.

Heat Exhaustion and Heatstroke

Problem: Symptoms range from heavy sweating, clammy skin, nausea, and dizziness (heat exhaustion) to high body temperature, confusion, and loss of consciousness (heatstroke). These are serious medical conditions.

Fix: At the first sign of heat exhaustion, stop running, find a cool, shaded area, lie down with feet elevated, loosen clothing, and rehydrate with cool water or an electrolyte drink. If symptoms worsen or resemble heatstroke (e.g., confusion, very hot skin, no sweating), **seek emergency medical attention (999 in the UK) immediately.**

Chafing and Blisters

Problem: Increased sweat in hot weather can worsen friction between skin and clothing, or skin on skin, leading to painful chafing, especially under arms, inner thighs, or around the bra line. Wet feet are also more prone to blisters.

Fix: Apply anti-chafing balm or petroleum jelly to susceptible areas before your run. Wear moisture-wicking, seamless running gear. For feet, ensure your running socks are synthetic and designed to wick moisture, and that your shoes fit well to minimise movement and friction.

Sunburn

Problem: Painful, red skin, peeling, and increased risk of skin damage from UV exposure during your run.

Fix: Apply a **broad-spectrum SPF 30+ sunscreen** 20-30 minutes before your run to all exposed skin. Wear a hat and sunglasses for additional protection. Reapply sunscreen if your run is long or if you're sweating heavily. Choose shaded routes whenever possible.

Fatigue and Reduced Performance

Problem: Feeling unusually tired, heavy legs, and a noticeable drop in pace or endurance compared to cooler weather runs.

Fix: This is a normal physiological response to heat. Accept that your pace will be slower. Prioritise effort over speed, take walk breaks, and don't try to push through extreme fatigue. Focus on completing the distance safely, rather than hitting specific speed targets.

Advanced Tips for How To Run In Hot Weather

Acclimatisation

If you anticipate running in hot conditions regularly, gradually exposing your body to the heat can improve your tolerance. Start with shorter, slower runs in the heat, increasing duration and intensity over **10-14 days**. This process helps your body adapt by increasing plasma volume, improving sweat rate, and lowering core body temperature during exercise. Be patient; acclimatisation takes time.

Pre-Cooling Strategies

Before a run, especially a longer or more intense one, try to lower your core body temperature. This can involve wearing a **chilled vest**, taking a **cool shower**, or consuming **slushies or ice drinks** about 30-60 minutes beforehand. This 'pre-cooling' can extend the time before your body reaches a critical heat level, potentially improving performance and comfort in the early stages of your run.

Electrolyte and Sodium Loading

For very long runs (over 90 minutes) or races in extreme heat, some runners consider a strategic approach to sodium and electrolyte intake. This might involve consuming saltier foods or a slightly higher concentration electrolyte drink the day before, or using salt tablets during the run. However, this strategy should be approached cautiously and is best discussed with a sports nutritionist or medical professional, as individual needs vary greatly.

Ice Bandanas and Cooling Towels

Beyond simply drenching a hat, specialised cooling towels or bandanas can be soaked in cold water and worn around the neck or head. These are designed to stay cool for longer through evaporative cooling. Some runners carry small ice packs in pockets or sports bras for strategic cooling during ultra-distance events.

Track Your Hydration

For more precise hydration, you can try weighing yourself before and after a run to estimate sweat loss. For every kilogram (or 2.2 pounds) of weight lost, aim to consume approximately **1-1.5 litres of fluid**. This helps to understand your individual sweat rate and tailor your hydration strategy more accurately for future hot weather runs.

How To Run In Hot Weather FAQ

Is it ever too hot to run?

Yes. While individual tolerance varies, generally, if the temperature is above **30°C (86°F)**, especially with high humidity, it's advisable to rethink your run. Consider moving your workout indoors to a treadmill or choosing a different activity. Always check official heat warnings issued by meteorological services.

How much water should I drink?

There's no one-size-fits-all answer, as sweat rates vary hugely. A general recommendation is to drink **5-7 ml of fluid per kg of body weight** in the 2-4 hours before exercise. During a run, aim for **150-250 ml every 15-20 minutes**. Post-run, replace 125-150% of fluids lost, based on weight change.

Can I still drink coffee before a run in the heat?

Caffeine is a mild diuretic, meaning it can increase urine output. While moderate caffeine intake is generally safe for habitual users, it's wise to be extra mindful of hydration. Ensure you're well-hydrated before consuming coffee and monitor how you feel. Some runners prefer to avoid it or reduce their intake on particularly hot days.

What's the difference between heat exhaustion and heatstroke?

Heat exhaustion is less severe. Symptoms include heavy sweating, pale skin, nausea, dizziness, and muscle cramps. Heatstroke is a medical emergency, characterised by a very high body temperature (over **40°C**), hot and dry or moist skin, confusion, and potential loss of consciousness. Heatstroke requires immediate emergency attention.

Should I wear a heart rate monitor?

A heart rate monitor can be a useful tool to gauge your effort in the heat. Your heart rate will naturally be higher for the same pace in hot conditions, so it can help you adjust your effort without overexerting yourself. However, don't rely solely on it; always listen to your body's overall signals.