Hundreds of children and old people have been hospitalised and thousands of animals killed in a cold snap in north Vietnam, as temperatures fell to 36-year lows. Media report today said people from various provinces needed medical treatment for respiratory and other ailments in recent days, while the agriculture ministry said more than 4,000 buffalo and cows have died in the cold. In the capital Hanoi, crowds gathered outside clothing shops as chilly customers rushed to buy thick jackets. On Wednesday, Mau Son mountain in Lang Son province bordering China dropped to minus 3.6 degree Celsius, the lowest temperature since a 1975 record of minus 3.2 degree Celsius.Hanoi saw a January low of 7 degree Celsius on Tuesday night. Weather forecaster said Vietnam is influenced by weather systems from the northern hemisphere, Europe and China but the exact cause of the current cold snap was unclear.