Elderly Hongkongers were warned to protect themselves against the cold yesterday, with the Observatory forecasting temperatures will drop to 12 degrees Celsius by Thursday. In a recorded message from the Senior Citizen Home Safety Association, the 80,000 elderly members of the community support service were reminded to take measures to keep warm in the coming days. "And they can just press a button when they need help," an association spokeswoman said, referring to the emergency system installed in members' homes that connects them to its service centre. The Centre for Health Protection also issued a warning to elderly people and those with chronic illnesses - including hypertension, diabetes and endocrine disorders - to wear warm clothing and keep up their exercise to boost blood circulation during the cold snap. "Cold weather can easily trigger illness, especially among the elderly and those suffering from heart disease, respiratory or chronic illnesses," a spokesman for the centre said. "The elderly have less insulating fat beneath their skin to keep them warm, and their body temperature control mechanisms may be weaker." Temperatures are expected to plunge into the low-to-mid teens this week, and it will be cloudy with a few rain patches as an intense winter monsoon arrives over the coast of Guangdong province, the Observatory says. Temperatures dropped to 14.5 degrees in urban areas this morning, according to the Observatory, the lowest this winter. But it is expected to warm up again on Saturday, with the temperature forecast to reach 20 degrees again by next Tuesday. The Observatory last month said it expected a warmer and wetter than usual winter due to El Nino, a climate phenomenon associated with warming in the central Pacific Ocean.