Dont sit in the driver's seat. Then you dont look like you are a suspicious loiterer, you look like someone left behind waiting for someone. Plus if you are drunk it will be harder to prove you had any intent in driving but regardless do not drink in winter you lose body heat even if it makes you feel warmer.
Winter face the windows toward the sun for passive heating. Summer face the car away from the sun and use sun shades. This is passive solar heating and cooling. For winter you want large canisters or jugs of water with a little vinegar in it to prevent mold, these should be black or otherwise dark in color, this is to be used as a passive heating where you store sunlight heat into the water, this is a trick used for greenhouses. Make sure there is some room for expansion from heat so dont fill entirely with water or put a balloon on the cap tied on maybe if it wont risk falling over, this is just a precaution against it bursting the lid off if it builds up enough heat. If the car has black seats have some white covers over them in summer so they dont get so hot.
Before modern A/C classic cars had straight up swamp coolers. So if you want to save on power you can try and make a car swamp cooler. It's just rags, air flow and water and a container to hold the water. Only works in dry climates though.
Sardines provide calcium and keep well. Dont over eat them since a lot of salt in them. Bakeries and donut shops sometimes let you take stuff for free instead of them throwing it out and often just a little stale.
Wear sunscreen or keep your skin covered. Car windows usually do not have filters for blocking UV light so you could easily get sunburned.
If you have it wearing wool, linen, silk, hemp. These all have antimicrobial properties and are good at keeping you warm and cool yes you can wear wool in summer in fact it's how most men dressed in the past. I've found polyester smells awful when it gets sweaty plus it has all these microplastics.
Is your car petroleum or diesel?
Clovis said:If there's a Walmart in your area, I heard you could park in their parking lots overnight (though it would probably be a good idea to use a low profile spot).
I know some restaurants chains accept government assisted funds or EBT, just in case you're ever in need of a warm meal.
I heard Walmarts arent ideal. While many do allow RVs to park and stuff the stores tend to be stolen from a lot so some management are hostile or wary to people and have security guards. A Home Depot or Lowes may be better bet or if having a gym membership then a parking lot of a 24 hour gym maybe ?
@Nette does this sound right? The home improvement stores have donated in efforts against homelessness so it would look bad if they were hostile to homeless people, right?