You can add the oil directly to the bath water and to your pillow cases and many other items (some people will take a small amount of oil on a bath cloth and add that to the cloths dryer - replacing expensive cent sheets)
Since you mentioned a heat rash - I would also suggest using something called lavender hydrosol - it is not just lavender water, but a product produced during the actual distillation of lavender oil. It is much stronger than lavender water, yet mild enough for everyday use. I keep bottles by my computer and pillow case for relaxation.
The lavender products are good for two conditions - healing of skin as well as relaxation.
Check out Leelanau Lavender Breezes, an organic lavender farm in Michigan. They make and sell a number of organic lavender products. I get my stuff through them. They also have lavender soaps that might be very good for you (especially the Aloe/Lavender) . Then you do not even need to put the oil into the water.Can I apply lavender essential oil directly to bath water?
Yes, you can use it directly in the bath water, sometimes it doesn't mix well with the water, well because oil and water don't mix and sometimes it will leave a ring or film around the tub depending on how much you put in. I always mix mine with bath salts, to prevent that, but it's totally fine just to add it straight to the water. Just drop some oil on the salts and mix it a little and then add it to the water. The salts will be good for rash too.
It depends on how deep and big your bath is.
If it is like spa size then several drops are needed to take the effect.
The heat rash will definately benefit from Lavender EO but try not to make the water temp too warm.
Some Roman Chamomile will also be soothing to your skin.
As for dilution the water is already doing that.
Don't add any soap and just lie back, relax and enjoy this magical moment of bliss.
Allow me to clear up your confusion. Both of the things you read are completely correct.
1. Yes, you can put a few drops of lavender oil into water.
2. If you use lavender oil on your skin directly you must dilute it with a carrier oil such as almond oil or olive oil.
i use about 5-10 drops in my bath daily and I have never had a problem! I use it straight out of the bottle without diluting it...so go ahead...try it and if your skin is ok, then don't dilute it...if you have a heat rash you might want to use oatmeal in your bath that will soothe it
To add to the other answers...
Lavendar is the ONLY essential oil that you can use neat (without diluting it ) all others must be diluted. Lavendar does not even need to be diluted in a carrier oil.
put a couple of drops in the running water.
you can dilute EO with any oil.
Use apricot for making perfume
It's perfectly safe to add to your bath water. You only need a few drops though thats pleanty.