Yeast stiffness is increased by heat-shock at 42 °C. Young’s Modulus (YM) determinations on an unstressed (A–C) and a heat-shocked cells (A’-C’). The white squares showed in the height images, (z range = 2 μm) (A, A’), indicate the localization of the elasticity maps shown in (B, B’). Histograms of the YM distributions (C, C’) associated with the elasticity maps. YM medians were calculated by fitting a Gauss model (indicated by the black curves).