In this experiment, we crossed temperature (20, 25, and 30C) with humidity (95% RH) and measured the effects on bumble bee (Bombus impatiens) water balance. We had 10 replicates per treatment, with 6 source colonies, resulting in a total of 540 bees. We placed bees singly into tubes and checked for mortality every 2 hours for the first 12 hours and then every 4 hours until 5/10 bees from each temperature, humidity, colony treatment had reached mortality (52h and 48h for the two trials). We measured mass before and after mortality to evaluate water loss and then dried bees to a constant dry weight to get the initial water content and dry mass of each bee.