Your brother's best bet is to take extra layers of shirts and pants, any thermals, any gloves and hats you possibly already own, as well as the thickest coat you can find and use this as initial clothing for entry into Harbin China, and then ditch it for better local winter gear once you leave the airport or checkin to your destination.
If your brother intends to be there more than a few days, I would suggest buying a coat and related gear from a local retailer in Harbin. He will still need to have the warm coat and related gear he arrived in at the airport. Retailers will have the warm gear he is looking for, in Harbin China. The clothes he will find in South Africa will probably not be adequate enough for such a harsh and extreme winter in Harbin China. I travel from Texas to Russia every January and have found that it's much cheaper to ditch my American gear and simply buy the heavy local winter gear in those places where it's cheaper and better quality.
In Harbin your brother will find wool products that are always the best choice for extreme cold weather.
There is also an article from the Harbin Ice Festival that covers Tips for Winter Dress for Harbin Travel
Tips for Winter Dress for Harbin Travel
Packing for winter travel to
Harbin to see the world-famous Ice Lantern Festival can be difficult.
All the gear it seems you'll need to keep yourself protected from
bitter winter can weigh you down, but if you leave anything behind you
can sorely regret it, especially if your finances or location don't
allow you to purchase suitable replacements. Follow these tips for
packing for winter travel in Harbin and keep yourself from freezing.
Pack a Warm Coat
Harbiners who are used to brutal winters wear coats made of fur, wool,
or other insulating materials. Unfortunately, these coats can be
bulky, heavy, and expensive. You may be better off purchasing a good
quality down coat that can be flattened to fit into your luggage. Any
coat you do buy should be longer than waist length and windproof.
To pack a down jacket (or other coat), find a large sealable bag.
After placing the coat in the bag, press all of the air out and seal
the bag. This will save you space in your suitcase.
Don't Forget a Hat
The traditional Chinese Northeastern-style fur hat complete with ear
flaps doesn't only represent a funny stereotype. These hats are
designed to protect the wearer's head and ears from the bitter cold
weather. Some sort of head covering will be essential for winter
travel to Harbin. Choose a hat for its practical qualities. You may
find that the traditional style hat, or a version of it, offers both
protection and style... once you get used to how you look in the
Wear Snow Boots or Waterproof Shoes
A pair of warm, comfortable boots or shoes may be the most important
accessory you take with you when you travel to Harbin during the
winter months. The coldest months in Harbin can see heavy snowfall.
Whether wet or dry, the snow can be deep and may not melt off until
spring. Make sure the boots you take cover the ankle so that you don't
get wet feet while trudging around in the snow.
Boots or shoes are best purchased well before traveling to Harbin
during the winter so that they can be broken in. They should be
comfortable enough to walk long distances in and able to accommodate
your feet and heavy, warm socks both.
Winter socks aren't just for outdoor use, either. If you suffer from
cold feet while just sitting indoor, as many people do, take a look at
the socks that you will take to Harbin.
Those one-size-fits all gloves that cost a few dollars won't keep your
fingers from freezing as you visit the parks (most are the venue of
the Harbin ice and snow festival) or enjoy skiing in the ski resorts
in Harbin. Purchase well-insulated gloves made of quality materials
that fit well and cover the wrists.
A woolen scarf tucked into your coat can protect your neck and throat
and block chilly winds. It is better to have a coat with a high collar
than to depend upon a scarf to protect your neck from the cold, but if
you don't have a coat with a high collar, bring along a scarf that is
long and warm enough to be useful against the weather.
Harbin use a centralized heating system to heat residential buildings,
so despite bitter winters, the temperature can be quite hot indoors.
While you'll need to wear warm clothing when going outside, you'll
want to be comfortable inside. The best way to insure that you don't
freeze while outside and don't boil inside is to wear sweaters that
can be removed if opening the windows doesn't cool off the room enough
for comfort's sake.