Unfortunately, not everyone has an oven to heat things in, whereas microwaves can be easier and cheaper to come by. Not to mention the time convenience of using a microwave. But I agree it would be a healthier option.
Awa
In the last few years we have switched from plastic to glass containers for this and similar health reasons.
I also find the caffeine-aspirin-tylenol (Excedrin) combination works for headaches, but not necessarily for my migraines. Usually I can tell the difference between my headaches and migraines and treat them as soon as I feel it and figure out which it is. If the Excedrin doesn't work, I will dip into the triptan prescription but all of them give me a nasty side effect of stiff neck and just feeling weird, so I end up taking a muscle relaxer and lay down and nap in a cool, dark room until the effects and headache subside. I recently started taking the shot Emgality monthly as a preventative. So far it seems to work well with the only side effect being a mild localized reaction where the shot was (and the shot hurts like a @_&^#+!!!) But it goes away shortly. Hoping to avoid needing to use the triptan/muscle relaxer combo as it just steals my day(s) away.
It's been up into the high 90's F (33+ C) Luckily I have mini-split air conditioning units in the various rooms of my home. We try to keep the bedroom cool with AC, fans, and blackout curtains. To conserve energy, we raise the temp during the daytime when not in the room. Similarly, we close off the rooms we aren't using and just us a reasonable AC temp in the occupied rooms.
I am thankful I work indoors in a temperature controlled environment, so I can't really complain. Been avoiding meals that require a lot of stovetop cooking to reduce heat from that source. Lastly, keeping a water source nearby and keeping hydrated.
I am more worried about my chickens. While they do have shade, it is still blazingly hot, so I have a cheap mister I found on Amazon that helps keep them cool.
If it's not hot, it is humid with storms. Been trying to avoid outdoor activities between 10 am and 7 pm.
About 3 years ago my husband and I stopped reheating anything in plastic containers. We still use them to store food in, but mainly have switched to glass containers.
We also invested in good water bottles that we use daily when in transit or at work.
We don't really use straws much but have been gifted reusable straws and occasionally use them, mostly for guests.
We recycle and have become more conscientious over the years in making greater attempts to avoid purchases that involve environmental contaminants.