Your water heater should be set for a temperature of 120 to 125 degrees at the kitchen sink (recommended by dishwasher manufacturers).  Having the temperature set too high could be dangerous.   It takes the following time for the water temperatures to give you a second or third degree burn:

                                                160 degrees                           About 1/2 second.

                                                150  ”                                      About 1 1/2 seconds.

                                                140  ”                                      Less than 5 seconds.

                                                130  ”                                      About 30 seconds.

                                                120  ”                                      Over 5 minutes.