Important reasons to change
At 30°C, you might be tempted to lower the temperature, but you can reduce it considerably, down to 20°C. Yes, you can wash at this temperature without any problem. There are special programs for this, and modern washing machines are very efficient; so even at this temperature, the wash will be impeccable. Your clothes will last longer, and the colors will stay vibrant.
In short, there’s not much reason to continue washing at 40°C. These days, you risk damaging expensive clothes that you’ll have to replace more often, and you’ll waste energy. Nobody wants that, right? So why not put aside your preconceived notions and try washing between 20 and 30°C?