Just beyond the south west entrance to Kootenay National Forest are the Radium Hot Springs, perfect for a rest before continuing on to Banff or the surrounding regions.
Fed by a natural hot spring, this facility has a cool (84 degrees) and a hot pool (102 degrees). You can even rent swim suits for about two dollars if you didn't plan ahead.
If you arrive at the park gates during a busy time and you won't be making any other stops in the park, you can use the left lane and blow past all the people waiting in the right line to pay for park admission. Just using the Radium Hot Spring facilities requires no additional park admission even though it's within park boundaries.