Is drinking cold water in hot weather dangerous?

During the hot season in Thailand, it is important to be vigilant about health, especially for those who have health problems. The high temperature during this period can be dangerous. Recently, there have been reports of heatstroke and people fainting due to the hot weather. Unfortunately, we also encounter misleading information that is spread on social media.

Several Facebook users have shared a warning message about dealing with hot weather. The message translates as follows:

"Prepare to cope with temperatures of 40-50 degrees. Drink clean water slowly and avoid cold or ice water. Currently, Malaysia, Indonesia, and Singapore are experiencing heat waves.

Here are some tips on what to do and what not to do:

1. The doctor advises against drinking cold water when the temperature reaches 40 degrees Celsius, as it may cause small blood vessels to rupture or explode. In one case, a man who came from outside and was sweating profusely washed his feet with cold water. This caused his vision to blur, and he had to call an ambulance.
2. If your body temperature reaches 38 degrees, allow your body heat to dissipate. Drink warm or hot water slowly and do not wash your legs, hands, or exposed skin immediately. Wait at least 30 minutes before taking a shower.
3. In one case, a man rushed to take a shower in the heat. After finishing, he experienced stiff legs and had a stroke. Warning: If you are feeling weak or in hot weather conditions, it is recommended that you avoid drinking cold water immediately. This is because it can cause small blood vessels to constrict, potentially resulting in a stroke. Please teach your children to be cautious."

Source | Archive

The aforementioned message has been widely shared on social media.

As this text has been widely shared, we have conducted further investigations. We have searched for various studies related to this issue to see if there are any reports of symptoms similar to those mentioned, such as heat stroke caused by drinking cold water in a high-temperature environment.

Expert Opinions

According to Dr. Richard Santos, President of the Philippine College of Emergency Medicine, the above post contains some correct information but creates a false link between stroke and drinking cold water in hot weather. In an interview with AFP, he explained that cold water can cause blood vessels to constrict as a physiological response to cold stimulation. However, there is no evidence linking drinking cold water directly to stroke, whether caused by blocked or ruptured blood vessels.

Moreover, Dr. Santos stressed that it is important to stay hydrated when staying in a high-temperature environment for a prolonged period of time during the hot season. There is a risk of dehydration, so it is recommended to drink enough water. Furthermore, drinking cold water may be risky for people with pre-existing medical conditions, although this is uncommon and the likelihood of experiencing negative effects from drinking cold water is minimal.

Furthermore, Dr. Santos advises social media users not to follow advice that suggests "letting the body heat up." Instead, he explains that one should limit the time spent in high-temperature environments. Our bodies can regulate temperature by being in a high-temperature environment for no more than 30 minutes to an hour. Therefore, if staying in a high-temperature environment for an extended period, it is necessary to cool down the body immediately to reduce temperature.

Dr. Jose Paciano Reyes, a neurologist and president of the Philippine Neurological Association, stated that blood vessels in the brain will not rupture upon contact with cold temperatures. He explained that immersing oneself in cold water or taking sudden cold showers may lead to "Cold Shock," which can cause loss of control of breathing, constricted blood vessels, and sudden increase in blood pressure.

Drinking cold water and taking a shower "is usually not a problem for people who are healthy," according to Dr. Reyes. Drinking cold water has benefits such as cooling the body, preventing excessive heat, and reducing inflammation. However, Dr. Reyes warns that drinking cold water immediately after being in a high-temperature environment may not be a good idea for people with heart disease, as it may increase their risk of heart disease and stroke. This is due to an increase in blood pressure and the heart working too hard. (Read more about this here).

Dr. Carla Robinson is a family physician and medical malpractice specialist in North Carolina. She works as a media consultant and medical writer for the Centers for Disease Control and Prevention (CDC). According to Dr. Robinson, when feeling too hot, you can relieve symptoms by drinking cold water or cooling down the body with cold water. In an interview with wcnc.com, she also stated that headaches or dizziness due to extreme heat are often caused by heat exhaustion or heat stroke, not from cold drinks.

Last year, due to hot weather conditions in America, these messages were widely circulated. Dr. Robinson explained the truth about the misunderstanding in this video.

Meanwhile, in Thailand, Dr. Jessada Denduangboripant, the lecturer of the Biology Program, Faculty of Science, Chulalongkorn University, has disputed the widely shared message mentioned above, stating that the message is not true. He explained that "Our body has a mechanism to maintain body temperature close to 37 degrees Celsius. Therefore, even on extremely hot days, if we drink cold water, we may feel a chill as the cold water moves through the esophagus. If the water is too cold, the brain will command blood vessels to contract and muscles to shiver to adjust the body temperature back to 37 degrees Celsius.”

Self-care during Extreme Heat

The Centers for Disease Control and Prevention (CDC) recommends that people drink more water during hot weather, limit outdoor activities, and find ways to cool off such as using air conditioning or swimming to lower body temperature. People can also take a cool bath or use a regular bathtub. (Read the full article from the CDC here.)

The Better Health website provides several methods for coping with and reducing body temperature during extreme heat. These methods include staying hydrated, keeping cool, and avoiding direct sunlight during the hottest times of the day. Other recommendations include wearing loose-fitting, light-colored clothing and paying more attention to vulnerable groups such as the elderly and young children. For more information, you can read the full article here.

In conclusion, it is important to stay cool and hydrated during hot weather to avoid heat exhaustion or heat stroke. Drinking cold water can provide temporary relief from feeling too hot, but it is not the cause of any heat-related illness. It is important to take care of yourself during extreme heat by staying hydrated, staying cool, and avoiding direct sunlight during the hottest times of the day.