The recommended temperature to wash underwear varies depending on the source. Some sources suggest washing at 60°C to kill bacteria and fungi, while others recommend washing at lower temperatures to avoid damaging the fabric. The NHS recommends washing high-risk items such as underwear at high temperatures of 60°C to kill bacteria and germs in the washing machine, thus limiting the risk of infection. However, washing at 60°C takes a lot of energy, and you risk damaging delicate materials or letting colors run. Therefore, washing at 40°C is also an option, but it may not be the most thorough antibacterial clean. Ultimately, it is best to follow the instructions on the care label of the underwear, as the manufacturer knows exactly at what temperature the fabric can be washed.