I agree with reflex - my little girl also likes her bath water a bit hotter than lukewarm. My mom did this when she bathed her the first time in baby's first month - my mom dipped her hand in the water and patted baby's stomach lightly and said "the water is just nice, there's nothing to be afraid of (BU PA BU PA), let's enjoy the bath!"
by the way, my little girl loves her grandmother (my mom) bathing her every once a week! nowadays I also pat my girl lightly to say "bathing now ok!" (CHONG LIANG LO!) she loves it! She's 4 months old now.