"just to be on the safe side, don’t press your face against the window"

Just to be on the safe side, don’t press your face against the window and keep your head at least one foot away from the oven. Radiation decreases rapidly with distance.
The History and the Research:
After some 20 years of research into their use, Soviet Russia banned the use of microwave ovens for heating food in 1976 as they decided that the dangers outweighed the benefit of speed.

The following is a summary of the Russian investigations that resulted in the banning of microwave ovens referred to above, published by the Atlantis Rising Educational Center in Portland, Oregon. Carcinogens were formed in virtually all foods tested. No test food was subjected to more microwaving than necessary to accomplish the purpose, i.e., cooking, thawing, or heating to insure sanitary ingestion.

Microwaving prepared meats sufficiently to insure sanitary ingestion caused formation of d-Nitrosodienthanolamines, a well-known carcinogen. Microwaving milk and cereal grains converted some of their amino acids into carcinogens. Thawing frozen fruits converted their glucoside and galactoside containing fractions into carcinogenic substances. Extremely short exposure of raw, cooked or frozen vegetables converted their plant alkaloids into carcinogens. Carcinogenic free radicals were formed in microwaved plants, especially root vegetables.

They were allowed again from 1987 when, under Perestroika, Gorbachev allowed many western business pressures to change problematic Russian regulations that did not fit in with "Western Free-Trade" practice.
https://www.powerwatch.org.uk/rf/microwaves.asp