With the haze, many people are flocking to traditional Chinese medicine shops to pick up herbs for brewing soups and drinks.
At the Hockhua Tonic chain, its general manager James Teo says sales of its bottled herbal drinks have increased by more than 30 per cent, along with those of pre- mixed herbal tea ingredients and chrysanthemum.
Sales of bird's nest have also increased by about 10 per cent. Other products such as white fungus, mung bean, barley, ginseng tea and cordyceps have also been popular.
He says: "During the haze in 2013, items such as green mung beans, barley, chrysanthemum, honeysuckle and white fungus went out of stock."
As a result, the company monitors the haze conditions closely and, depending on the severity, it will increase imports of these products.
For the Eu Yan Sang (Singapore) chain, managing director Serene Seow also notes a spike in sales, particularly for Essence of Chicken infused with cordyceps and ginseng. Other popular items are honey and herbal drinks and herbal jelly.
But are these herbal remedies effective in combating the haze?
Respiratory specialist Chew Huck Chin from Mount Elizabeth Novena Hospital says: "There is no definite scientific data on drinking cooling teas to relieve haze-related symptoms, but they are of no harm. In certain patients, drinking these teas hot can help relieve throat irritation."
He also suggests building up immunity by eating foods high in vitamins C, E and omega-3 fatty acids. More importantly, he advises cutting down on coffee and alcohol, as they "promote fluid loss and leech nutrients from the body".
He also suggests avoiding dairy products and red meat.
"These diets have been associated with an increased inflammatory response," he adds.
The Family Dietitian's Jackie Green also suggests avoiding sweetened drinks such as bottled green tea, lemon tea or sodas.
She says: "The haze can make people feel sluggish, so avoiding processed foods high in fat and sugar, which may add to that feeling, would be wise. These include pastries, fries and burgers."
Housewife Michelle Fong, 55, who has been buying herbal and barley drinks for the past few weeks, says she is cooking more herbal soups for her family and cutting down on deep-fried food: "You can't really avoid the haze, but at least we can minimise its effects by eating and drinking well."
5 THINGS TO EAT AND DRINK
1 Nuts and seeds
Nuts and seeds such as sunflower seeds, almonds (left) and quinoa are rich in vitamin E, which helps to boost the immune system. They can be incorporated into cereal or eaten on their own.
2 Vegetables and fruits
Vitamin C can be obtained from vegetables such as kale (left), bell peppers and cabbage. Orange juice or a cup of berries would also suffice. Mix up the colours to get a full range of nutrients. For example, vegetables and fruits in the orange category would include pumpkin, sweet potato, carrots, peppers, and mango.
3 Oily fish
Oily fish such as salmon (left) are rich in omega-3 fatty acids, which reduce inflammation and enhance the immune system. Other alternatives include sardines, mackerel or fish oil.
Water, hot or cold, is important for keeping hydrated in this weather. Water infused with lemon slices or mint leaves (left) can help soothe sore throats.
5 Cooling teas
Pick up some cooling teas from traditional Chinese medicine shops. Chrysanthemum and wolfberry teas can help soothe throat inflammation.
•Tips from respiratory specialist, Dr Chew Huck Chin, from Mount Elizabeth Novena Hospital and lead dietitian Jackie Green from The Family Dietitian at the Osteopathy & Podiatry Centre in Forum (Office Tower).