There are certain things Malaysians recognise immediately.

That slightly burnt smell when you step outside. The sky looking strangely white even though it isn't cloudy. Someone in the family WhatsApp group asking, "IPU berapa sekarang?" And, inevitably, somebody else replying with a screenshot before you've even had time to check.

Jerebu is back in the conversation again this October, and this time it has already started changing everyday routines. Earlier this month, unhealthy Air Pollutant Index readings were recorded across multiple areas in Peninsular Malaysia. Schools have had to monitor conditions and suspend outdoor activities when readings rise.

For those of us who've lived in Malaysia long enough, the routine is familiar. Outdoor plans become indoor plans. The windows stay shut. The air purifier suddenly gets promoted to most important appliance in the house. Parents start checking the air quality before deciding what the kids can do outside.

Still, familiarity can make us a little too casual about it.

Jerebu isn't only an annoying smell or the reason KL disappears from the window. The haze contains fine particles and pollutants in the air, and prolonged exposure can cause symptoms such as coughing, sore throat, irritated or watery eyes, runny nose, itchy skin and breathing difficulties. Children, older adults and people with respiratory or heart conditions can be more vulnerable.

So while we're waiting for blue skies to make their comeback, this feels like a good week to make life slightly gentler.