In the event of a large-scale crisis, emergency and response teams cannot assist all businesses, institutions, or citizens at the same time. Therefore, it is advisable to take your own precautions. On the Emergency Preparedness page, you can learn how to prepare for heat waves or other crises.

In its brochure *Heat Etiquette*PDF-File1,61 MB, the Federal Environment Agency recommends, among other things, the following:

• Avoid physical activity, especially during the hottest part of the day (around 11 a.m. to 6 p.m.) and when ozone levels are high. Postpone shopping, physical activities, or sports until the cooler morning and evening hours.

• Ventilate only early in the morning and at night. During the day, windows, blinds, and curtains should remain closed. Exterior window shading, such as roller shutters, provides more effective protection against heat than interior shading (such as curtains).

• Cool your body using simple methods such as a cooling foot bath. Cooling body lotions or a thermal water spray can also provide relief.

• Make sure that neither you nor others stay in parked cars during hot weather

• Some medications lose their effectiveness in the heat. Store your medications in a cool, shaded place. Follow the instructions in the package insert, and if in doubt, ask your doctor or pharmacist. Never stop taking medication on your own, and do not change the dosage or the time of day you take it.

• Look out for those around you during a heat wave. Be especially helpful to older people, those who are ill, or those living alone. 

In its brochure *Heat Etiquette*PDF-File1,61 MB, the Federal Environment Agency recommends, among other things, the following:

• You don’t feel thirsty until you’ve already lost a significant amount of fluid. You should therefore drink at least one glass of water every hour, even if you aren’t thirsty. Recommended beverages in hot weather include tap water, mineral water, chilled herbal tea without added sugar, and tea with mint and lemon. Do not drink these beverages ice-cold.
• In Wiesbaden, more than 60 stores and facilities offer tap water for free. You can fill your water bottle with it, ensuring you always have water with you while on the go. You can find an overview of all so-called refill stations on the “Cool Places” map (opens in a new tab). 
• Avoid coffee, sugary drinks, and alcoholic beverages (including beer), as they cause the body to lose fluids.
• Eat light, fresh, and cool foods. Eat several small meals with as high a water content as possible, such as fruits, vegetables, and salads.
• Avoid or reduce your intake of protein-rich foods such as meat, fish, dairy products, legumes, and nuts, as they increase body heat.

In its brochure *Heat Etiquette*PDF-File1,61 MB, the Federal Environment Agency recommends, among other things, the following:

• Wear loose-fitting, lightweight, and breathable clothing. This allows air to circulate around your body.
• Light-colored clothing reflects sunlight. This keeps your body from heating up as much as it would in dark clothing.
• Make sure there is a gentle breeze around you. Use a fan or a hand fan. When outdoors, protect your head in particular by using sunscreen with UV protection, sunglasses, and a hat, as the brain is especially vulnerable to overheating.

During a heat wave, keep an eye on those around you, especially older people, those who are ill, or those living alone. Talk to people in your community and make them aware of the dangers of the heat.

Call older adults, people who are ill, or those living alone at least once a day to check on them. Ask if they’ve been drinking enough fluids and how warm it is in their home. Visit your loved ones more often on hot days to spot signs of heat stress early on. 

Take advantage of family networks and neighborhood support groups whenever possible. If available, use local (social) platforms that facilitate mutual support on hot days.

High temperatures put a strain on the body. Older adults are often particularly at risk.

As we age, our metabolism changes. The body regulates its temperature more slowly. That’s why older people often sweat less or start sweating later. However, sweating is important for cooling the body down.

Food & Drink

• As you age, the sensation of thirst diminishes. Once the body becomes dehydrated, it recovers only slowly. Drink two to three liters daily, even if you don’t feel thirsty. An alarm or a note can remind you if needed.

Clothing

• Wear light clothing in hot weather. Cotton and linen are suitable for warm days, while nylon and polyester are less so. Wet towels or cold foot baths provide additional cooling. Water sprays or cool water on your wrists can refresh you throughout the day. Sunglasses and headwear, such as a sun hat or cap, protect your head and eyes.

Other

• Some medications lose their effectiveness in the heat. Store your medications in a cool, shaded place. Follow the instructions in the package insert, and if in doubt, ask your doctor or pharmacist. Never stop taking medication on your own, and do not change the dosage or timing of your doses.
• Avoid the midday heat. Schedule sports or strenuous activities, such as gardening, for early morning or evening. Sunscreen with an SPF of 30 or higher protects your skin from UV rays. Seek out shaded and cool places, such as parks or air-conditioned rooms, to give your body a break.
• Take advantage of family networks and neighborhood support systems whenever possible. If available, use local (social) platforms that facilitate mutual support on hot days.

Pregnant women, infants, and toddlers are particularly at risk during heat waves. Babies under one year of age should not be exposed to the sun but should always stay in the shade. Neither babies nor children should ever be left alone in a car.

Food and Drink

• During hot weather while you’re pregnant, drink at least two to three liters of water a day, even if you’re not thirsty.
• If you’re breastfeeding, nurse your baby more frequently and make sure you’re drinking enough yourself. If you’re bottle-feeding, offer formula more often on hot days.
• Offer older children something to drink with every meal, such as water or unsweetened tea. Remind your children to drink regularly in a playful way or by taking drinking breaks together. Avoid ice-cold beverages. Children between the ages of two and six need at least one liter of fluid daily; when temperatures exceed 30 degrees, they need at least up to three liters.

Clothing

• As with everyone else, the same applies to pregnant women: Wear loose-fitting, lightweight, and breathable clothing. This allows air to circulate around the body. Light-colored clothing reflects sunlight. This keeps the body from overheating as much as dark clothing does. Heat can cause a pregnant woman’s legs to swell quickly. Therefore, wear comfortable shoes, drink enough fluids, and elevate your legs from time to time. 
• Dress your baby in a thin long-sleeved onesie, light-weight long pants, socks, and a sun hat. The hat should shade the face and neck. Diapers trap a lot of heat. If you don’t want to go without them entirely, let your baby kick around without a diaper from time to time when it’s hot.
• In hot weather, airy clothing made from natural materials like cotton is sufficient for children—and for babies as well. Avoid clothing made from synthetic fibers. A wool-silk blend is particularly suitable, as it helps regulate body temperature. 

Other Tips

• Protect the sensitive skin of pregnant women and young children with a mineral-based sunscreen with SPF 50.  
• Avoid the midday sun between 11 a.m. and 3 p.m. Stay in shady and cool places with your children. On the map of cool places, (opens in a new tab) you’ll also find playgrounds with water and mud play areas.
• Always keep strollers or bike trailers in the shade. Avoid using cloths or blankets in front of the stroller or trailer, as they trap heat. A parasol or sunshade is a better option. For baby carriers, use a thin, light-colored cloth. Avoid dark-colored cloths, as they absorb heat.

On the geoportal, you’ll find a map of cool places (opens in a new tab). The map shows locations in Wiesbaden that offer relief from the heat on hot days, such as parks, fountains, streams, and playgrounds with water features. There are other cool places not listed on the map: shopping centers, supermarkets, museums, and hotels, for example, are often air-conditioned as well.

Heat can cause serious health problems (cardiovascular issues, regulatory disorders), which in extreme cases can lead to fatal heatstroke. To prevent health complications, prompt action is necessary.

• If you experience symptoms such as nausea, dizziness, headaches, or fatigue, you should contact your family doctor’s office or the on-call medical service at 116117.
• If you experience symptoms such as clouding of consciousness, loss of consciousness, new-onset confusion, repeated vomiting, or a body temperature above 39 degrees Celsius, you should call the emergency number 112.

It's not just people who suffer during heat waves—animals do, too. 

• Provide dogs and cats with several water bowls filled with fresh water. Make sure there are shaded resting spots both indoors and outdoors. Animals should stay indoors as much as possible. Only walk your dog early in the morning or after dusk. Asphalt can get very hot and burn their paws. You can have dogs with thick coats carefully shaved after consulting with your veterinarian.
• Provide full shade for enclosures housing rabbits, other small animals, and poultry. Place frozen water bottles inside to help them cool down, along with water-rich fresh foods such as cucumber or fennel. Never place cages on the windowsill.
• Horses, cattle, and other grazing animals need shaded areas, such as a shelter or densely leafed trees. Fresh water must be available at all times—30 to 50 liters per animal per day. Schedule intensive riding training for the cool morning or evening hours. After riding, slowly rinse the horse with cool—not ice-cold—water. Fly masks and fly rugs reduce stress caused by insects.
• Install air pumps or fountains in garden ponds to ensure sufficient oxygenation. Plants or shade nets protect against overheating. Do not place aquariums in direct sunlight, and turn on fans or cooling units as needed.
• Providing a watering spot in the garden or on the balcony helps birds, squirrels, insects, and other wildlife. During long heat waves, this can even be a lifesaver. Keep the watering spot clean. Change the water daily and clean the trough regularly with hot water and a brush. Pathogens can multiply rapidly in small pools of standing water. Insects also depend on water. Place stones, pebbles, or small twigs in the watering spot. They provide insects with a secure foothold and protect them from drowning. 

Climate change has caused a noticeable rise in the average air temperature in Wiesbaden. Since the 1990s in particular, strikingly high air temperatures have been occurring with increasing frequency. Between 1961 and 1990, the long-term average was 9.8 degrees Celsius; from 1991 to 2020, it rose to 11.1 degrees.  

For several years now, we have also been experiencing long, dry heat waves in Wiesbaden during the summer. These pose a health risk, especially to the elderly, young children, and the sick. Heat causes asphalt to crack and damages road surfaces. Agriculture suffers from drought and loses large portions of the harvest. In the weakened city forest, bare patches are spreading because bark beetles are infesting the spruce trees. Drought is increasingly leading to forest and field fires. Low water levels in the Rhine and Main rivers not only affect wildlife but also hinder shipping and, consequently, the economy. At the same time, heavy rainfall and flooding are on the rise.

The German Weather Service has studied the urban climate of Wiesbaden and Mainz as part of the Klimprax project. The models show that by 2060, the number of summer days, hot days, and tropical nights in Wiesbaden will increase significantly. The results of the project are available from the Hessian State Office for Nature Conservation, Environment, and Geology (opens in a new tab).
 

To better protect people from summer heat, the city has developed a heat action plan for Wiesbaden. It is based on the Hessian Heat Action Plan (HHAP) (opens in a new tab) and has three main objectives:

• First, groups particularly vulnerable to heat are to be protected during heat waves. The plan outlines what information each group needs, how to reach them, and who is responsible for providing it.
• Second, the general public is to be educated and made aware of heat protection measures and the dangers of heat.
• Third, the plan aims to implement long-term measures against extreme heat. For example, the plan includes proposals on how public spaces and parks in Wiesbaden can be better equipped to withstand heat and drought.

The Heat Action Plan is regularly updated and revised as needed. For more information, visit wiesbaden.de/hitzeaktionsplan (opens in a new tab).

There is no universally accepted definition of the term “heat wave” internationally. According to the German Weather Service (DWD), a heat wave is characterized by a period lasting several days with unusually high thermal stress.

Heat waves pose a significant health risk, especially for the elderly and people with health conditions. For this reason, the DWD issues warnings through its heat warning system (opens in a new tab). The DWD distinguishes between two warning levels for heat warnings.

• Level 1 Heat Warning: A Level 1 heat warning is issued when the heat index exceeds a certain threshold in the early afternoon. The threshold is approximately 32 degrees Celsius, but may be slightly lower during early summer events due to an acclimatization effect and slightly higher in midsummer. Another criterion for issuing a warning is the nighttime temperature inside buildings. This is because if the night remains too warm, sleep quality deteriorates. This additional strain makes it harder to cope with the heat during the day.
• Level 2 Heat Warning: If the perceived temperature exceeds 38 degrees Celsius in the early afternoon, a Level 2 heat warning is issued.

You can find more information on this in the DWD’s Frequently Asked Questions (FAQ) (opens in a new tab).

A tropical night is a night during which the minimum air temperature is at least 20 degrees Celsius. The daily measurement period runs from 6:00 p.m. to 6:00 a.m.