May I humbly suggest you'd have significantly better luck removing stains if you didn't wash in hot water. it will set most protein-based stains and doesn't really help the others. Hot water is effective if you are washing whites with bleach. Beyond that, it does more harm than good.

I have often wondered, why hot water.

Some few decades ago I got a washer that gave me the option and I never found any benefit from hot water.

Hot water dissolves the detergent better - one of the prime reasons it is used, it also puts more dirt and grime into suspension, taking it away from the clothing.

I still question that it causes more harm than good, I've never seen that and given the average person's body tempreture + air tempreture I doubt hot water damages clothing. Unless you're washing your clothes in 130F water, it seems likely that a day wearing a t-shirt in Macon Georgia would hurt the fabric more than a 20 minute soak in soapy 110F water.

While one's core body temperature approaches 100° and that is often the air temperature here in Sacramento, neither conduct the heat as well to the proteins of the stain as well as soaking in hot water. My hot water heater is set to 125°, significantly higher. If you would like to see the difference such small degrees of difference can make, take two glasses of milk (use smooth, clear glass glasses, if possible) and drink both. Allow the remaining milk in the glass to air dry over night. Soak one in cold water for ten minutes and the other in hot from the tap for the same amount of time. See which is easier to wash. My experiments clearly show the soaked in cold vastly easier. I believe, if I remember my high school chemistry class, thank you Mr. Dryer, the process is called coagulation. Exactly what that means has left the brian, but the word remains.