Hi, I don't know about infrared saunas, and seeing as your posting was in June, I hope that you've found relief for your son by now. If not, or things are repeating, here are a few things to try:
What was very effective for my two daughters was this:
(All of these ingredients are available at Whole Foods, albeit not cheaply! I mention this because it is important to tackle the problem right away, without waiting for ingredients through the mail.....) Otherwise, they breed, lay eggs and it is a rapidly compounding problem!
For the actual treatment, begin in the early evening preferably:
Mix 100% Neem Oil with 100% tea tree oil, 50/50
1) I used an eye dropper to apply this oil mixture directly to the scalp. Make sure the hair is dry while you are doing this. Massage the oil in very well, making sure to coat the whole scalp as well as possible, especially behind the ears, the nape of the neck, etc. For grown-ups, you can also add in Peppermint oil, but it's not recommended for kids. The Neem does have a powerful smell, which my daughters, 8 and 4 years old, really didn't care for, LOL.....Here is a link to why neem works:
http://www.pureneem.com.au/neem-for-people/info_13.html
The best excerpt from the article is this passage:
Neem has been shown to rid the body of head lice in three very important and distinct ways. First of all, Neem contains hormone mimics that interfere with the life cycle of parasites. Secondly, Neem inhibits the parasites’ ability to feed, giving rise to the term anti-feedant. Finally, and very importantly, Neem prevents louse eggs from hatching.
2) Next, for the hair at large, I used virgin coconut oil, largely because it is less expensive than Neem/tea tree and I had more of it. Then, cover the hair with a close fitting bathing cap, and leave on for several hours, preferably overnight. The essential oils will penetrate the shells of the lice, and will also make it easier to slide off the nits, later. I don't think that the lice actually drown--I think that they are good at holding their breath for a long time. Also, there is a stage where the nits don't need to breathe air, and thus those nits wouldn't be suffocated anyway.
3) The next morning, shampoo the hair with tar shampoo to wash out all of the oils and bugs (I have heard good things about Zinc shampoos as well, but haven't tried them myself.) I had my girls lie on the kitchen counter, one at a time, and used the sprayer of the kitchen sink. I did it over a white basin so that I could really see what came out of their hair. You don't have to shampoo so well that the scalp is squeaky clean. It is better if the scalp remains slightly oily, which will help with the removal of the nits and stop lice from attaching more eggs.
4) Towel dry the hair. Sit the kid in front of a movie, as this next part can be quite laborious. Shine bright lights on the head, and arm yourself with a good pair of close reading glasses. (Or a magnifying glass, but the reading glasses are better because they leave both hands free. Now, you start nit-picking, going through every little tiny bit of hair and removing the eggs. I have heard that there is a spray that will make them either white or bright pink and therefore easier to see:
http://www.neonnits.com
It sounds like it could be a really great product, though perhaps harder to use on blond hair.
I nit-picked on my girls for three days in a row, and then moved into doing it every other day. I temporarily saved the nits that I picked, to see if any of them would hatch, but none of them ever did, most likely because of the Neem. (I figured it was better safe than sorry and that I shouldn't only trust the Neem to kill the eggs-better to remove them. Since the night when I used the Neem, I have seen no more live insects.
We did a second night three days later using virgin coconut oil and bathing caps, just in case there were any eggs or nymphs at other stages of development.
Also, on nights when they had dry hair, I had them wear hair covers, too, that I laundered and dried on high heat every day, plus putting a heavy towel over their pillow and changing it every day. This is to prevent nits/lice on the bed from getting on to them, and to prevent nits/lice on them from getting on the bed.
I've did visual checks of my husband's hair, and he did visual checks of my hair, and neither of us saw any lice at all. I did all of the same protocol on myself that I did for the girls, especially because I spend so much time with them, except the nit-picking (which you really can't do to yourself!!!! It is important to thoroughly check all family members and perhaps even some friends, as some folks don't even get itchy and don't really know that they have them. Throw non-washable stuff in plastic bags for two weeks or more, so that the nits have time to hatch and then die without a meal.
It is important to be somewhat repetitive about the hair oiling/nit-picking, just in case, to collapse the cycle.
The nit-picking can be pretty brutal, but very important, as one missed egg can start everything up again. It was well worth it to get the doctor's note saying that the kids can go back to daycare/camp!!!!
What is really depressing is that all it takes is one contact with another child with lice and everything can start up again. With this in mind, I have ordered some Lice R Gone shampoo (which is an enzyme mixture that causes the lice to spontaneously molt, plus which dissolves the nit glue.) The plan is to use it weekly as a prophylactic measure against future re-infection, but we will have to say more after actually using the product!
I will also get some zinc lozenges for them, which is also supposed to help repel the lice from internally.
I am thankful that we were able to become lice free quite rapidly, thanks to the Neem!!!!!! (Our very first (and stupid) action was to try Rid from the drugstor, and, what do you know.....IT DIDN"T WORK! We followed the directions to the letter and were still left with many live insects. The next day, on the internet, I learned about the resistance lice have to the stuff and the serious danger the poisons pose to small children. YIKES!--The next action, much smarter action, was to get the Neem oil the next day.)
Hope that this is helpful, either to you or to others who are trying to rid themselves of lice.
When we try the things that we don't yet have experience with, perhaps we will report back about what the verdict on those was.
Good luck!