As typhoon Nakri swirls away from Shanghai, the summer heat is returning to the city.

After the city experienced cooler temperatures over the past weekend, the average high has jumped back to around 35 C this week, causing local authorities to send out reminders on buses and metro trains that warn residents about the dangers of heat-related illnesses.

Shanghai experienced the hottest July in 140 years last year. With continuous heat alerts issued and temperatures surpassing 40 C, the city's disease control center reported that more than 10 people died from heatstroke in that month. Although the heat is less severe this year, doctors are still calling on residents to take precautions.

Dr Stephen Misch with Parkway Health has more than 20 years of experience in emergency care. He told the Global Times that there are several types of people who are most susceptible to heat-related illnesses. They include athletes, construction workers, the very young and the very old.

"Old people are more fragile," he said. "Their bodies can't respond as well. And they are not sensitive to dehydration. When younger people get dehydrated, they will feel thirsty. But an old person can be quite dehydrated and still not feel thirsty. By the time old people feel thirsty, they are usually very dehydrated."

The doctor said that babies are just as vulnerable, but what's trickier is that they cannot express themselves. He suggests that parents check to see if their babies are sweating a lot or if their skin is turning bright red.

Athletes and construction workers run a higher risk of heat-related illness because they spend so much time outside. Sometimes, athletes are burdened with equipment like shoulder pads. Every year around this time, it is also hot and humid in the US, but American football players carry on with their training, Misch said.

The stages before heatstroke

"Every year in August, we hear about high school students getting heatstroke or even dying," said the doctor, who worked at hospitals in Michigan and California for more than 10 years before moving to Shanghai.

The National Institute on Aging, a division of the National Institutes of Health in the US, also lists obese people, alcoholics, patients with heart, lung or kidney diseases and people with high blood pressure as susceptible to heat-related illnesses.

Heatstroke is the most severe type of a heat illness, Misch said. Before this happens, there are two other stages that one might experience, namely heat cramps and heat exhaustion. Heat cramps are muscle contractions, often in the abdomen or hamstring. The contractions can be violent and painful. "For this mildest condition, if one slows down, gets out of the sun and drinks a lot of water, the symptoms will improve," Misch said.

The next stage is heat exhaustion. If sufficient attention is not paid to a heat cramp, Misch said other symptoms might follow, such as dizziness, nausea and confusion. Sufferers can look pale and might even faint. "One would feel much more tired than he is supposed to be," he said.

But the doctor said there are still many things that someone with these symptoms can do. "You can take off as many clothes as possible, ideally just down to your underwear. Get yourself wet with any type of water you can get. You can even get into a shower, but it's better to be cold or coolish water, not warm. The water will carry away a lot of the heat for you," he said.

Treatment and prevention

The doctor said that the traditional Chinese practice of scraping a person's neck, chest or back also makes sense to him when it comes to alleviating these heat illnesses. "The scraping irritates the skin, which means more blood to the surface while normally it is inside. When it is really hot, one can shift the blood to the surface so that he can get rid of some of the heat," he said.

If no immediate measures are taken, the condition could develop into heatstroke, a life-threatening problem. The doctor suggests that someone should call an ambulance as soon as possible because the sufferer is probably delirious. "A person with heatstroke has a very high fever, above 40 C. And paradoxically they won't be sweaty," he said. "They can be very dehydrated so maybe they don't have any more sweat. Their skin can get very dry. People can fall unconscious."

Misch said that when offering first aid to heatstroke victims, one can lay the person down on the ground, take off as much of their clothing as possible, and put ice bags under their arms or under their neck. But given this is a medical emergency, these patients will still need IV fluids for rehydration.

To prevent any type of heat illness, the doctor suggested that people pay close attention to their bodies, such as observing the color of their urine or the frequency of their bathroom visits. "If you find the urine is too dark or the last time you went to a bathroom was four hours ago, your body is telling you to drink more water. People don't suddenly go into heatstroke over 20 minutes. It takes hours to get there. If we pay attention, we can intervene to avoid it," he said.



 

Local authorities remind residents to take precautions against heatstroke on hot summer days. Photos: CFP