Passive smoking is associated with an increased risk for cardiovascular events. However, the exact mechanisms by which passive smoking affects cardiovascular health are not entirely understood. In the present study, the researchers investigate the effects of short-term exposure to secondhand smoke on platelet function and peripheral microvascular endothelial function in healthy individuals. For this purpose, platelet function and endothelial function are measured before and after a 1-hour exposure to secondhand smoke in a concentration that is encountered in bars and restaurants without smoke-free policies. The researchers' hypothesis is that short-term exposure leads to platelet activation and impairment of endothelial function.