I brewed my first batch by just sprinkling dry yeast on the surface and it took about a full day to show even the initial signs of activity.
You're always better off by making a starter wort a day of two before brew day to get the yeast active and multiplying. A simple wort like 10:1 (2 litre of water : 200 grams of DME) boiled for 15 minutes and cooled to room temp, pitch the yeast and cover with aluminum foil or an airlock in a large enough vessel to allow some room at the top. Pitch the starter into your full batch of wort at preferably no higher than your expected fermentation temperature and within a few hours you should (but, not always) be able to see visible signs of fermentation. This helps the yeast start out strong in that huge volume of wort.
I wouldn't try putting any type of yeast into 105 degree water, unless you're trying to mass murder billions of little beer makers!