What Happens After I Do Work

Sounds a bit like POTS, especially since it's after a temperature change (shower) and happens when you get up. Does it go away when you lay down?

I'm just recently learning more about POTS so it's just a guess.

Apparently salt helps some.

Also saw an article about POTS after covid, but forgot to read it.

WBF - I figured out the welts I had were from yellow jacket stings. They must have not gotten full stings in as a few days ago I was mowing again, and this time I could se them and they hit me hard. So that explains the welps.

As far as what you describe how you feel after working, I get some of those feelings often. I have no trouble standing up or walking after, but my feet can hurt, ankles feel tight and though my legs feel like they'd be weak, they aren't. I'm able to walk or run up stairs or ride a bike, though my legs feel a bit tight.

As you have seen, I have a positive on EMG and NCV for large fiber neuropathy. Not suggesting you have that as you would have some pain and weird sensations with it.

POTS could theoretically cause blood to pool in the legs and cause inflammatory symptoms there (weakness, soreness, heaviness, etc. in the feet, legs, and joints). This also would fit with the timing because the physical labor might dehydrate you and deplete electrolytes, which make POTS flare. I would expect that you might notice other symptoms from POTS as well, like a more rapid heart rate upon standing and possibly lightheadedness, but you don't mention those things, so I hear you that it makes sense to look at more ideas.

I wonder if you have any issues in your lower spine. It's possible to have compressed or irritated nerves in your lower spine that cause weakness and soreness all the way down your legs. My mother's feet and legs were symptomatic for years before her lower back itself began to hurt from the nerve compression. Any chance your car seats or a chair you use often is compressing your tailbone or lower back region, and that the physical labor irritates those areas and causes inflammation?

Seems important that the symptoms you're experiencing are in the lower body only.

Someone mentioned electrolytes, so I started doing something about it. I have done heavy labor a couple times since and sweated profusely. I took a break while working and took a potassium and magnesium glycinate capsule and ate a little restaurant packet of sea salt. I didn’t notice having those same reactions after doing that.