You don't buy lukewarm water, you heat water until its lukewarm.
The water in the bathtub was lukewarm.
The swimming pool's water was lukewarm.
Water is lukewarm when it is slightly above your temperature, about 100-105 degrees F.
The warmer of the two would be hot water. Tepid water is nearly body temperature, so it is considered lukewarm. That means that hot water is hotter than lukewarm water.
The benefits of drinking lukewarm water is that your body doesn't have to cool the water from hot water or warm up the water from cold water. This saves energy and does not put stress on your body.
Loelekh Vosser.
Perhaps about 75 or 80 degrees Lukewarm is generally around body heat. ≈ 36 oC or 98 oF
Tepid is lukewarm water so obviously hot water!
Lukewarm honey may be honey that is warmed in tea or hot water. This is used for medicinal purposes to treat sore throats and colds.
Check the temp on your hot water heater, you can turn it up.
make sure the water is lukewarm to the touch. Do not use hot or cold water
Replace the shower valve.