Running in Indian heat and monsoon: staying safe

Running in Indian summer and monsoon is safe if you adjust the time, the pace and what you drink, and if you know the signs that mean stop. Humidity matters as much as temperature, because sweat that cannot evaporate cannot cool you.

Why heat and humidity change the rules

WHO explains that the body struggles to lose the heat it makes when conditions are hot, humid, still or strongly radiant, and that heat-trapping clothing adds to the load. That is why humidity matters, not only the number on the thermometer. WHO also lists athletes among those who face heat stress from exertion.

India's weather department (IMD) bases heat wave warnings on air temperature alone and does not report wet-bulb temperature, which combines heat and humidity, according to an explainer in Citizen Matters (written in 2022, so check IMD for current practice). IMD's heat wave criteria in that explainer: 40 degrees or more in the plains, 30 degrees or more in hilly regions and 37 degrees or more on the coast. So a day can feel dangerous before an alert appears.

Choose your time and read the alerts

• NHS advises avoiding direct sun between 11am and 3pm and avoiding strenuous exercise in the heat. WHO also advises avoiding strenuous activity in the hottest part of the day.
• Check the IMD forecast and warnings. Per Citizen Matters, yellow means heat wave conditions in isolated pockets and a concern for vulnerable groups, orange is a severe heat alert with high health risk for people exposed to sun or doing heavy work, and red is an extreme alert where heat illness is very likely in all age groups.
• On orange or red days, we suggest moving your session indoors or skipping it. That is our suggestion, not an official running rule.
• Be patient in the first hot weeks of the season. Lower your pace and distance until you feel comfortable; WHO warns that heat stress can worsen heart and kidney conditions, so talk to a doctor if you have one.

Drinking: enough, not too much

NHS says dehydration shows up as thirst, headache, dizziness, dark yellow strong-smelling urine and tiredness, and suggests pale urine as a sign you are drinking enough. It also recommends drinking more when sweating from heat or exercise.

The opposite mistake is real. A consensus statement summarised by Newswise says to avoid drinking more than you lose through sweat and urine, with the simple rule "drink only when thirsty." It lists low body weight, women, novice runners and slow runners (especially race times over four hours) as higher-risk groups for exercise-associated hyponatraemia, and says extra salt from sports drinks or salt tablets does not seem to lower the risk if you overdrink. If you run long in the heat, talk to a doctor or coach about your own plan.

Clothing

NHS suggests loose, light-coloured clothing in the heat, and WHO lists light, loose-fitting clothing too. Choose what keeps you cool and comfortable.

Signs of heat illness, and when to stop

NHS describes heat exhaustion as tiredness, dizziness, headache, nausea or vomiting, heavy sweating with pale clammy skin, muscle cramps, a raised temperature, intense thirst and irritability. If you notice this, stop running. NHS says to move to a cool place, remove extra clothing, sip water or an oral rehydration drink, cool your skin with water and fanning, and stay with the person. They should feel better within about 30 minutes.

Heatstroke is different. NHS lists a very high temperature, hot skin that is not sweating, fast breathing, confusion or restlessness, seizures and loss of consciousness, and states that heatstroke is a medical emergency. Call local emergency services at once. Also call them if someone is still unwell after 30 minutes of rest, cooling and fluids. Never run through these symptoms.

Running in the monsoon

• Be seen. ASICS and RunVan both note that rain makes it harder for drivers to see you. Wear bright or reflective clothing, and a brimmed cap helps keep water from your eyes.
• Slow your steps. Wet roads are slick. RunVan suggests smaller, quicker steps and attention to footing, and both sources say to avoid large puddles, which can be deeper than they look.
• Choose grip. RunVan recommends shoes with enough grip for wet pavement. See our guide on running shoes for Indian roads.
• Protect your feet. RunVan suggests carrying a dry pair of socks, since dry feet blister less. NHS says to wear moisture-wicking socks and change them often if your feet sweat, and to break in new shoes gradually. More in beginner running injuries.
• Stay aware. Healthline recommends wearing one earbud or none so you can hear traffic.

A simple plan

1. Check the forecast and any IMD alert the evening before.
2. Run early or after sunset, on shaded or familiar routes.
3. Slow down in humidity, and drink to thirst.
4. Stop at the first signs of heat illness.
5. If you have a medical condition, ask a doctor what is safe before the hot season.

New to running? Our 5K plan for India eases you in, and a run club gives you company on hot days. Treqz Run, coming soon, is not available yet.

This is general information, not medical advice. Talk to a doctor about your own health.

Sources

• NHS: Heat exhaustion and heatstroke
• NHS: Dehydration
• NHS: Blisters
• WHO: Climate change, heat and health
• Citizen Matters: IMD heat wave data, alerts and wet-bulb temperature
• Newswise: Statement on exercise-associated hyponatraemia
• ASICS: Tips for running in the rain
• RunVan: 5 tips for running in the rain
• Healthline: Running in the rain

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