The main purpose of washing clothes is not only to get rid of the sweat odour from your clothes. It is more about getting rid of harmful bacteria from the clothes. They make you sick if they are allowed to breed.
If any of your family member is ill, then that person's fecal remnants on the clothes contain viruses and bacteria.
So what? Is it so dangerous? Well, even a gram of the fecal remnants may have millions of micro organisms. And if other family members are exposed to the microorganisms, they may get affected. Does it make sense now?
Even though you thoroughly wash and wipe after passing bowels, your underwear will still carry a gram of the fecal matter!
And when you are sick, your underwear may carry harmful micro organisms. If you have the habit of allowing your family members to wash your underwear, you are passing on a health risk.
If your inner wear is being washed along with the clothes of other family members, the risk of passing on the germs to others would increase.
And then comes how you wash the underwear. Hand wash or machine wash? If you are using a washing machine, the germs will get into the washing machine and get into other clothes.
A study claims that some types of micro organisms survive the conditions inside the washing machine. They won't die. They may later cause respiratory issues or flu.
One way to minimise the risk is using high temperature to dry the clothes in the dryer. You might need to dry it for more than 20-15 minutes in the dryer after setting it for high temperature. If you have hot sun in your area, sun dry the clothes. UV rays can do a better job.
If an infected underwear is washed in the washing machine, don't wash other clothes in it immediately. Just rinse the machine with soap water and disinfectant and run a wash cycle.
You don't need to worry about washing clothes when nobody in your family is down with any type of sickness. And don't forget to wear gloves when touching infected underwear.