We investigated the effect of a temperature shift from 23˚C to 37˚C, mimicking the temperature transition experienced by a microbe as it enters a human host. This strategy allowed the exploration of protein expression changes in a short term response to a temperature upshift and to characterize the suite of proteins required to respond to a 37˚C host in the first few hours. We demonstrate that a significant number of proteins are rapidly altered in expression within hours after a temperature shift. Many of these proteins are related to adhesion, biofilm formation, and immune evasion, suggesting that temperature serves as a sentinel cue to predict and prepare for niche adaptation in the host.