This article is unavailable. Low, D.A., Wingo, J.E., Keller, D.M., Davis, S.L. Zhang, R. and Crandall, C.G. (2008). Cerebrovascular responsiveness to steady-state changes in end-tidal CO2 during passive heat stress Journal of Applied Physiology. In press. If you wish to obtain a copy please contact the author below: David.Low@brunel.ac.uk