In Japan, there is a “maternity mark” used for asking for courtesy towards pregnant women in public places. It’s widely used in badges, cell-phone straps, posters, signs, etc., but unfortunately there are still some people who are ignorant about it. I’ve even seen a few men who started smoking even when there was a pregnant woman around. I know it’s sometimes hard to know a woman you see is pregnant or not, but smoking should be refrained in public places.
This badge detects smoke and glows blue with a sign “Don’t smoke!”. The faces on the badge change, too. It’s also good for the expectant mother because she can quickly notice the smoke and get out of there.
We could use the idea not only for smoke but for heat, coldness and some other harsh environments for expectant moms. But hopefully the people around the woman should know better without this.