Summer can be wonderful, but a real heatwave is not just an uncomfortable summer day. When temperatures go above 35°C / 95°F, and especially when they get close to or above 40°C / 104°F, the heat can affect your energy, your sleep, your travel plans, and your health.

As someone who’s going through a European heatwave right now, with temperatures over 40°C / 104°F, I wanted to update this guide with the practical things that help me and the official safety advice that is worth knowing.

Below you’ll find heatwave safety tips for home and travel, including how to prevent dehydration, how to recognize heat exhaustion and heatstroke, how to keep your home cooler without air conditioning, and how to adjust your day when the weather becomes too hot to ignore.

Heatwaves can be very dangerous, so here are my tips to help you stay cooler during hot weather. As you’ll see, they are useful when you’re at home, when you’re traveling, and even during hot summer days when the thermal comfort goes far beyond the comfort zone.

How to Stay Healthy During a Heatwave: Extreme Heat Safety Tips for Home and Travel

Know the warning signs of heat exhaustion and heatstroke

Before the prevention tips, it’s good to know the difference between heat exhaustion and heatstroke. According to the NHS, heat exhaustion does not usually need emergency medical help if the person can cool down within about 30 minutes, but heatstroke needs to be treated as an emergency. You can read the official NHS guidance on heat exhaustion and heatstroke.

Signs of heat exhaustion can include tiredness, dizziness, headache, nausea or vomiting, heavy sweating, pale or clammy skin, muscle cramps, high temperature, intense thirst, and irritability.

If this happens, move the person to a cooler place, remove unnecessary clothing, give them cool water or a rehydration drink if they can drink safely, and cool their skin with cool water, a spray, a fan, or cold packs wrapped in cloth.

Signs of heatstroke can include a very high temperature, hot skin without sweating, fast breathing, fast heartbeat, confusion, poor coordination, seizure, or loss of consciousness.

If someone has signs of heatstroke, get emergency medical help immediately. Keep cooling the person while waiting for help.

I’m adding this section because I know from experience that you can do many things right and still get into trouble. One time, we went to an air show — my son, my husband, and I. We had water, electrolytes, caps, and we were careful. We had been to that event before in previous years, and my son was 12, so he was not a toddler. Even so, after about three hours, the heat was too much for him and we had to go home. This was enough to remind me that heat illness is not something to push through just because you came prepared.

It happened to me too once, while doing necessary shopping and having to be outside around noon. I didn’t lose consciousness, but I felt bad enough to take it seriously. Electrolytes and medicine helped me then, but the main lesson was clear: when the heat starts affecting your body, stop, cool down, and don’t negotiate with yourself.

How much water should you drink during a heatwave?

The first step to avoid dehydration and heat exhaustion is to drink regularly, not to wait until you feel extremely thirsty. There isn’t one perfect amount of water for everyone, because it depends on your age, health, medication, activity level, humidity, and how much you sweat.

Try to drink water on a constant basis, as during a heatwave the body does its best to regulate its temperature, and thus more sweating is involved.

If you’re walking a lot, sightseeing, mowing the lawn, exercising, or doing physical work in the heat, small regular drinks are better than drinking a lot at once after you already feel unwell. For moderate activity in the heat, CDC/NIOSH workplace guidance mentions about one cup of water every 15 to 20 minutes, but I would not use that as a fixed rule for everyone sitting indoors. You can read the official CDC/NIOSH recommendations on heat stress and hydration.

You can also use water with minerals, electrolyte tablets, oral rehydration salts, or an isotonic sports drink if you’re sweating heavily. I don’t use them all the time, but during extreme heat or physical effort they can help replace some of the salts lost through sweating.

I admit that I’m not doing great on very hot summer days. I’m not good with heat, so even at 33–35°C / 91–95°F it’s too hot for me. During a heatwave, it is even worse.

If I’m at home and mow the lawn, for instance, that adds more pressure because it’s physical effort in heat. That’s when I’m more likely to add mineral or electrolyte tablets to my water, because I know I’m sweating more than I would while sitting indoors.

Reduce your coffee and caffeine consumption

I know that there are doctors who recommend cutting out coffee completely during heatwaves, but I like my morning coffee.

As I mentioned, heat is not my friend, so what I do is simple: I keep my morning coffee, but I don’t turn caffeine into an all-day drink.

I would avoid energy drinks, too many iced coffees, and sugary caffeinated sodas during the heat of the day. Water should be the main drink when it’s extremely hot, especially if you are outside, walking a lot, or sweating.

Don’t drink alcohol

Consuming alcohol during a heatwave is not a very good idea, because alcohol can make dehydration worse.

For me, it’s easy, as I don’t drink alcohol often.

If you like it more than I do, then at least try to avoid drinking it during the hottest part of the day, drink moderately, and alternate alcoholic drinks with water.

Avoid the hottest part of the day — or alternate with cooler indoor places

Official hot-weather advice often recommends avoiding direct sun between 11 a.m. and 3 p.m., when UV levels are high. During a severe heatwave, I would also avoid unnecessary errands later in the afternoon if your local temperature and heat alerts are still extreme.

Also, remember that official air temperatures are not measured with a thermometer baking in direct sun. Weather stations use protected, ventilated conditions so the reading reflects air temperature, not the temperature of pavement, walls, cars, or your skin in full sun. This is why a forecast of 38°C / 100°F or 40°C / 104°F can feel much worse when you’re walking on concrete, waiting at a bus stop, or standing in an open square.

While it’s best to follow the advice to stay out of the sun during the hottest hours, I know that there can be situations where you need to go outside during this time.

One of the ways to stay healthy during a heatwave is to limit your errands as much as possible.

If you need to go to multiple locations, then make sure you alternate going outside with periods of time spent inside where there is air conditioning or at least cooler air: shops, malls, libraries, pharmacies, supermarkets, museums, cinemas, cafés, churches, etc.

If you’re traveling during a heatwave, don’t keep the same itinerary you would use on a normal summer day. Move outdoor sightseeing to early morning or evening, check if attractions changed their hours because of extreme heat, and use the middle of the day for museums, indoor markets, churches, malls, cinemas, cafés, or a longer lunch break.

A walking-heavy itinerary can become too much very fast when the city is over 38–40°C / 100–104°F.

Eat hydrating food, including fruits

In Romania, we have a wonderful event: Bucharest International Air Show. It’s a one-day or two-day event and it takes place at an airport, obviously.

There are many airplanes, Romanian and special guests from other countries, that perform here throughout the day.

Each moment is special. It usually starts around 10 a.m. and ends around 10 or 11 p.m. with a concert.

It takes place during the summer, when it is hot. One of the ways to reduce the risk of heat exhaustion during this event is to eat hydrating food, including fruits.

I remember one year there was a mobile fast-food place that offered only fruit — not juice, but peeled or washed fruits to eat.

I ate many peaches, watermelon, and cantaloupe, and I managed to cope with the heat outside and stay hydrated during a hot summer day.

Fruits and cold foods don’t replace water, but they can help when the heat makes it hard to eat normal meals. Watermelon, peaches, cantaloupe, cucumbers, tomatoes, yogurt, cold soups, and simple salads are easier for me during a heatwave than heavy cooked meals.

Wear light-colored, loose clothing made from breathable fabrics

During the summer, and especially during very hot days, it is recommended to wear light-colored, loose clothing. Breathable fabrics such as cotton and linen usually feel better in extreme heat than tight synthetic clothes, because they allow more air circulation and help sweat evaporate.

I wouldn’t say that all synthetic fabrics are bad, because some sports clothes are designed for sweat and heat. But tight, heavy, dark clothing is usually a poor choice during a heatwave.

Wear a hat

Another way to protect yourself during a heatwave is to wear a hat, preferably a light-colored, wide-brimmed one.

During the summer, on hot days, I wear such hats not only at the beach, but also in the mountains, in parks, and at public events.

Does sunscreen prevent heatstroke?

Sunscreen does not cool your body and it does not replace shade, water, rest, loose clothing, or a hat. But it protects your skin from UV damage and sunburn, which can make a hot day even harder on your body.

Use broad-spectrum sunscreen and reapply it at least every two hours when you’re outside, especially if you sweat or swim. Don’t forget the ears, nose, back of the neck, hands, tops of the feet, and exposed scalp.

If you don’t use sunscreen, your skin can turn red, burn, or even blister, depending on the UV level, your skin type, and how long you stay outside.

Choose heatwave-friendly activities

If you’re an active person, or if you’re visiting a city during a heatwave, you can still do things — but you have to choose activities that fit the weather.

Instead of intense activity at the gym, you can go to a swimming pool. You can also choose to go to a bowling alley or an indoor place that has air conditioning, where your favourite sport takes place.

If you’re at home, you can do a puzzle outside if you have enough shade there, host a movie marathon for your friends in the yard in the evening, or play board games with your friends.

If you’re traveling, or you just want to go somewhere, you can choose to go to a coffee house or ice cream place with your favourite book. You can visit a museum, go to the mall, have a shopping spree, or see the latest movie at the cinema.

If the heat is extreme, I would not plan a day around outdoor queues, open squares, long walks, exposed viewpoints, or amusement parks with little shade. Those may be fine on a normal summer day, but during a heatwave they can become exhausting much faster than expected.

Cooling off in water can help, but don’t jump into unknown rivers, lakes, fountains, or unsupervised water just because you’re desperate to cool down. Choose supervised pools, official swimming areas, or safe beaches when possible.

How can you keep your home or hotel room cool without air conditioning?

If you don’t have air conditioning, the main goal is to block heat during the day and let cooler air in when the outside temperature drops.

During the day, close windows, curtains, blinds, and shutters, especially on the side where the sun hits. If the air outside is hotter than the air inside, open windows can make the room warmer, not cooler.

At night or early in the morning, when the outside temperature is lower than the indoor temperature, open the windows fully and create cross-ventilation if you can. Open windows on opposite sides of the home or hotel room, or use a fan near a window to move cooler air through the space.

Also avoid adding extra heat indoors. Don’t use the oven during the hottest part of the day, turn off unnecessary lights and electronics, and create one cooler room instead of trying to cool the whole place.

The British Red Cross has practical advice on how to keep your home cool during a heatwave, including keeping warm air out during the day, closing curtains and blinds, avoiding extra indoor heat, and creating a cool room.

For sleeping during a heatwave, I’d keep it simple: light bedding, breathable pajamas, a cooler room if you have one, and windows open only when the outside air is finally cooler. A lukewarm shower before bed can also help more than an ice-cold shower, which many people find uncomfortable anyway.

Use wet towels, cool packs, or a spray bottle

Some advice recommends cool showers, but I cannot do cold showers. If you’re the same, you still have other options.

One thing you can do to keep cool during a heatwave is to apply wet towels, cool packs wrapped in cloth, or cool water to areas such as your neck, wrists, armpits, ankles, and feet. These areas are easier to cool and are often recommended in heat first-aid advice.

You can also keep a small spray bottle with cool water and use it on your face, arms, legs, or clothes. It won’t replace getting into shade or air conditioning, but it can help you feel cooler for a while.

How do you know if you’re getting dehydrated during a heatwave?

Thirst is not the only sign of dehydration. During a heatwave, pay attention to how you feel and how often you pee.

Possible dehydration signs include feeling thirsty, dizzy, lightheaded, unusually tired, having a dry mouth, lips, or tongue, peeing less often than usual, and having dark yellow, strong-smelling urine.

I would not panic over urine color alone, because food, vitamins, supplements, and some medicines can also change it. But if your urine is dark, you’re peeing less, you feel dizzy, and you’ve been sweating in extreme heat, take it seriously. Start with small sips if you feel nauseous, move somewhere cooler, and ask for medical advice if symptoms are strong or don’t improve.

You can check the NHS list of dehydration symptoms, which includes dark yellow, strong-smelling pee, peeing less often than usual, dizziness, tiredness, thirst, and dry mouth.

Who needs extra care during a heatwave?

Heat can affect anyone, but some people need extra care: older adults, babies and young children, pregnant people, people with heart, breathing, kidney, diabetes, mobility, or mental-health conditions, people who live alone, outdoor workers, and people taking medicines that affect hydration or temperature control.

During a heatwave, check on people who may not be able to cool their home, get drinks easily, or notice early symptoms fast enough.

If you travel with medicine, check storage instructions too. Don’t leave medicine in a parked car, a beach bag in direct sun, or luggage sitting in a hot place for hours. If you use insulin, inhalers, or other medicine that may be sensitive to heat, ask a pharmacist what is safest.

Conclusion

A heatwave can affect your day much faster than a normal hot summer afternoon. Water helps, but it’s not the only thing: you also need shade, cooler indoor spaces, lighter clothing, sunscreen, rest, and a plan that fits the real temperature outside.

If you’re traveling, adjust your itinerary. If you’re at home, keep the heat out during the day and let cooler air in when the temperature drops.

And if someone shows signs of heatstroke, treat it as an emergency, not as something to “wait and see.”

FAQ: Staying Safe During a Heatwave

What are the first signs of heat exhaustion?

The first signs can include dizziness, headache, nausea, heavy sweating, tiredness, cramps, thirst, irritability, and feeling faint. Move to a cooler place, loosen clothing, sip cool water or a rehydration drink if the person can drink safely, and cool the skin.

How do I know if heat exhaustion becomes heatstroke?

Heatstroke is more serious and can include confusion, poor coordination, seizure, loss of consciousness, fast breathing, fast heartbeat, very high temperature, or hot skin without sweating. If someone has these symptoms, get emergency medical help immediately.

How much water should I drink during a heatwave?

There is no single amount that fits everyone. Drink regularly throughout the day and drink more if you’re sweating, walking, exercising, or working in the heat. Small regular drinks are usually better than waiting until you feel very thirsty.

Should I drink coffee during a heatwave?

I keep my morning coffee, but I don’t make caffeine my main drink during extreme heat. Water should be the main drink, and I avoid energy drinks or too many caffeinated drinks during the hottest part of the day.

How can I keep my home cool without air conditioning?

Close windows, curtains, blinds, and shutters during the day, especially on the sunny side. Open windows at night or early morning when the outside air becomes cooler than the indoor air.

Should I open windows during a heatwave?

Open windows only if the outside air is cooler than the air inside. If it’s hotter outside, open windows can bring more heat into the room.

What should tourists do during a European heatwave?

Move outdoor sightseeing to early morning or evening, check attraction hours, avoid long exposed walks, and plan indoor stops during the hottest part of the day. Museums, cafés, malls, churches, cinemas, and shaded parks can make the day safer and easier.

What are signs of dehydration during a heatwave?

Possible signs include thirst, dizziness, tiredness, dry mouth, peeing less often, and dark yellow, strong-smelling urine. Urine color alone is not perfect, but combined with heat, sweating, and feeling unwell, it’s a warning sign.

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Violeta Loredana

Violeta-Loredana Pascal is a communications expert, business mentor, and the founder of Earth’s Attractions and PRwave INTERNATIONAL. A pioneer in the Romanian digital PR landscape since 2005, she holds a degree in Communication and Social Sciences from SNSPA Bucharest. Violeta is a senior trainer at AcademiadeAfaceri.ro, where she leverages over 20 years of experience to teach professional courses in PR strategy and workplace productivity. By blending high-level business consulting with a passion for holistic travel and wellness, she empowers solopreneurs to overcome procrastination, build profitable brands, and design a life of purposeful adventure.