Why do children with cancer where a kind of mask over their face?

i have always wondered but never known

They don't wear them all the time, only when they are around other people or might become exposed to germs. Chemotherapy and radiation can temporarily weaken the immune system for a few days to a few weeks and during that time period kids and adults with cancer sometimes need to protect them selves from germs by wearing a mask. Either wear the mask .. or stay home and away from people.

so that they don't inhale the germs around them. their immune systems are weakened by the cancer.

Same as above, but radiation and chemotherapy weaken the immune system, so they try to avoid any germs.

for they want breathe in the air that surronds them with germs in it.

All of the above answers are correct. All cancer patients should wear theses masks to protect them self from germs while they are immunsuppressed. Adults where these also.

They wear a surgical mask to protect themselves from exposure to germs from others. When a person undergoes chemotherapy to treat cancer it weakens the immune system and makes them susceptible to infections.

All cancer patients are actually supposed when around people, during treatment when their blood counts are low. Just a lot of adults tend to ignore this precaution. I ignored it most of the time.

When people are being treated for cancer their immune systems get almost shut down so even the smallest germ could get them very very sick. The mask is a precaution so that the kids or adults are less likely to get sick.