How does hot weather affect our organism?
- High temperatures most negatively affect the respiratory tract of chronic patients (with COPD and asthma) and children. Breathing becomes heavy, and bronchospasms and irritating cough may occur.
- Blood vessels widen and blood pressure is reduced. Coagulation changes and frequent dehydration can cause local thrombosis; legs swell because of fluid retention in lower parts of the body.
- Sudden temperature changes can lead to myocardial infarction and, because of dehydration and weakened immunity of the skin, UV radiation can cause burns, cancer and premature aging.
- Exposure of eyes to too much UV light can lead to cataract.
- Fluid deficiency may affect kidney function and build-up of minerals from urine, causing kidney stones.
- If body and air temperature are similar, body cools by perspiration, which can change heart rhythm and cause dehydration and cramps.
Heatstroke is a sudden collapse of organism that occurs as a result of frequently abrupt and excessive increase in body temperature and the inability of organism to cool itself by perspiration and maintain temperature within a normal range, due to an extremely high outside temperature or heatwave.
Last decade has revealed a trend of rising summer temperatures that affect the health of the overall population. Timely measures can reduce the number of persons jeopardized by heat by alleviating possible negative health issues and acting instantly.
During heatwaves, please follow recommendations of local health authorities on radio, TV and internet.
How to behave during hot weather
- Cool yourself down and drink enough water to keep the colour of your urine bright.
- Drink regularly still water and low calorie drinks free of caffeine, alcohol and sugar to avoid greater dehydration. Refresh yourself by melting an ice cube in your mouth. Avoid dehydration by drinking diluted juice fruit such as lemonade: adults every 1-2 hours, and children 1-2 spoons or a sip of water every 15-20 minutes. Do not wait to feel thirsty to drink, especially if you are elderly and have less acute sense of thirst.
- Avoid direct sun between 10 a.m. and 5 p.m. This especially applies to children, pregnant women, elderly, heart patients, and patients with chronic diseases (mental disorders, diabetes etc.)
- Outdoor workers need to take a break in the shade more frequently and drink one and a half glass of water every 30 minutes.
- Have a shower or a bath in lukewarm water. You can also wrap yourself in cold wet towels or cool yourself down using a wet sponge, a foot bath etc. You can place wet towels on children’s hands and feet.
- Wear light loose-fitting clothes made of natural material. If you have to go out, wear a wide-brimmed hat or a cap and sun glasses, and to protect yourself from direct sun it is useful to have an umbrella or a fan with you.
- Your bed linen should be light, if possible without a pillow, to avoid accumulation of body heat.
- Eat more frequent small liquid meals. Avoid too much protein-rich food and, if you can, prepare mixed fresh fruit, a “smoothie”, or a light soup to replenish lost minerals, viamins and electrolytes.
Cool your home
- Try to cool your home, ideally by keeping temperature below 32°C at day and 24°C at night. This is particularly important for children, persons older than 60 years of age and people with chronic health problems.
- Use cooler night air to cool your home down. If possible, open all windows or raise window blinds or shutters during night or early morning hours, when external temperature is lower.
- Reduce the quantity of hot air in your flat or house. Close the windows and shutters during the day, especially those facing the sun. Turn off all light and as many electric devices as possible.
- Shade or cover windows exposed to morning or afternoon sunlight. However, do not forget that this increases air humidity.
- If you have an air conditioner, close the doors and windows to avoid spending more energy than needed. Adjust the temperature so that it is not more than 7˚C lower than outside.
- Electric fans can provide relief and refreshment, but if the air temperature is above 35˚C, they will not prevent heat-related health problems. They will, however, help speed up the air flow when you let fresh air circulate in the evening.
It is important to drink enough, as we lose more fluid when we sweat, which results in dehydration and increased blood viscosity that can cause thrombosis, brain injury or heart attack.
Avoid the heat
- Move to the coolest part of your flat or house, especially at night.
- If your flat or house are not cool enough, spend two or three hours a day in a cool place (e.g. public building).
- Avoid being out during the hottest part of the day.
- Avoid extreme physical exertion. If you can’t avoid it, do it when it is coolest, usually in the morning between 4 and 7 a.m., and after 5 p.m.
- Stay in shade.
- Do not leave children nor animals in a parked car.
- Regularly apply sunscreens to protect yourself from UV radiation. Special care should be taken of newborns and infants. They should be protected by sunscreens with the highest sun protection factor (>30) and dressed in lightweight clothes that also protect against UV rays.
- Adapt your exposure to sun UV radiation to daily UV index variations.
- If you drive, avoid travelling during the hottest part of the day.
- Visit your family, friends and neighbours who are often alone. Sensitive people and those with limited mobility might need your help during hot days.
- Talk about heatstroke with your family. All family members should know which protective measures they should take in view of their health condition and activities.
- If someone you know is at risk, help him or her get an advice and support. The elderly and patients who live alone should be visited at least once a day.
- If these persons take medicine, check how they affect thermoregulation and body fluid balance with their physician.
If you have health problems
- Keep your medicines at a temperature below 25˚C or in a refrigerator (read the section on safe drug storage in the package leaflet).
- Ask your physician for advice if you have a chronic disease or take more medicines, especially diuretics and antihypertensives.
If you feel unwell
- If you feel dizzy, weak, anxious or have intense thirst and headache, seek help, move to a cooler space, and take your temperature.
- Take sips of water or non-sweetened fruit juice multiple times.
- Relax and lay down in a cool room if you have painful cramps, most often in legs, arms or abdomen, which occur frequently after physical labour or exercise in very hot weather.
- Drink fluids containing electrolytes (e.g. soup, vegetable „smoothie“ etc.), and, in case cramps last longer than an hour, seek medical assistance.
- Talk to a physician if you have other difficulties or if problems described persist.
If a member of your family or people you help have dry hot skin or delirium (do not speak clearly or are confused), buzzing in their ears, vision problems and cramps and/or are unconscious, call a physician or emergency services immediately. While you wait for help, move the person to a cool room in a horizontal position, lifts his/her legs and hips, remove clothing and begin with body cooling – apply cold compresses to neck, armpits and groin and turn on electric fan, wave a fan or large piece of textile and sprinkle skin with water at a 25–30˚C temperature. Take temperature and keep it below 39˚C. Do not give this person acetylsalicylic acid nor paracetamol. Unconscious persons should be placed in the recovery position (lying on their side).
Check for warnings to possible heatwaves.
Important phone numbers for Croatia:
Ambulance – 194
Emergency communication centre – 112