Hi Valorie
Aha, the story is revealing itself… 
That’s very interesting about the poison oak episode. Perhaps there is some relation.
I was talking with a friend yesterday. During our conversation (with regards to some recent issues she’s been having) I discovered she eliminated salt from the diet of her whole family ages ago, believing as we all do that too much salt is bad for you.
That in itself is an interesting statement. And yes too much IODIZED TABLE SALT IS BAD FOR YOU. What is good for you however, is natural unrefined sea salt. In fact it’s essential.
I recommend going out and buying some proper salt! Try Celtic, Himalayan or Hawaiian. I am sure there are plenty of others and by all means go to a store where they sell them bulk and sample some. Then make sure you start to take about a teaspoon of the GOOD salt every day. You can sprinkle it on your salads, your meals, anything. Hey, even add a pinch to your water bottle to make it a great electrolyte drink.
I would also up your water intake. If you are only drinking 40 oz of water per day on non yoga days I do think that is not sufficient. See what you can do to take 60-70 oz per day, maybe even more. But keep up the salt too. Kids should have the good salt too. About 1/2 a teaspoon would be good depending on their age.
So, back to the conversation with my friend yesterday. I ended up bringing her some Himalayan salt later that day. And we both agreed there are 2 good reasons to buy that poisonous table salt: Making Play dough for your children and for adding to cold water when you are wanting to set dyes in clothes where the color runs! 
I would love to know if the salt and water make a difference to you. And how you go with your yoga, skin and what effect the heat experimentation has on everything.
Namaste
Gabrielle