Taking a hot bath/shower might help elevate it for a short while. Usually fatty, spicy, or salty foods should help increase blood pressure. Stay away from diuretics or any kind of herb that acts as a diuretic. The diuretics can cause mineral loss which can lower blood pressure. Sometimes eating excessive greens can even cause lower BP. Sodium and potassium levels in the body can relate to high or low BP.
Being in the hot sun can raise BP, whereas being in the cold can lower it. I’ve had to eat more salty/fatty foods/(some spicy on very cold days) in the winter to keep my blood pressure up due to my job being mostly outdoors. Very Low blood pressure can be very uncomfortable feeling where it can make you very disoriented and make you feel lightheaded almost to the point where you feel like your going to pass out. There’s been some instances in the past where I had to supplement with salt because my BP was getting to low. Some salty pork skins/sucking on some salty sunflower seeds will usually help. I try to stay away from the commercial pork skins because they can be fried in bad oil/fat(oil/fat that hasn’t been changed out enough).