It's a rare occasion when I wash any laundry in tap cold.
I usually wash things like throw rugs and perm press in warm - which in the Neptune is 105F. I figure this isn't much above body temp and if the fabrics can't take body temp then they shouldn't be worn in the first place.
Otherwise stuff like towels and sheets get washed hot - which in the Neptune is 130F. The tidy whities etc get washed in the Miele 1918A at 160F. Although it seems to me they get just as clean in the Neptune at 130F, although I've been known to "trick" it into an extra long wash cycle by programming in a hot pre-wash, and the longest wash cycle (34 min) as well.
Where is the energy savings if someone must wash a load twice in cold to get it clean?
One note about the hand washing story: yes, hands wash a lot faster in warm water. However, one's body temp will warm up a water and soap slurry on the hands rather quickly, so I find I can still wash my hands in tap cold and get them reasonably clean. And I do that frequently since the hot tap in the kitchen takes a while to warm up after a period of non-use, and I don't like running the tap forever just to wash hands that are already relatively clean.