There are many different enzymes, both natural and man-made/tinkered with, and just like other living creatures some enzymes are happy in temps that would bother others.
For instance there are enzymes that are quite happy in very hot conditions, such as natural hot springs/hot baths. Then there are those who are happy in cooler ranges.
In general, most enzymes used for laundry and automatic dishwashing work best between 100F and 140F, with 120F-140F being the sweet spot. Enzymes will work in cool and perhaps even cold water, but the activity will be slower and require more contact time.
Because of this "low" temperature range, detergents with enzymes clean just as well or better in most cases than the harsh alkaline/high temp detergents they replaced. Notice even on European front loading washing machines, the high temp range used to be 200F,and is now around 170F, if that. This is because enzymes combined with percarbonate bleach work well in "cooler" water temps. This is also a boon to automatic dishwashing detergents for machines in the United States, which use 120v power. Such machines rarely reach more than 140F wash temps (if even that, depending upon several factors), so enzymes will in general produce better results without the need for chlorine bleach (which was used because it attacks protein - the reason one cannot use it on silk or wool), and at "lower" wash temps.
L.