<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I think i've asked this first question before, but i searched for it and couldn't find it. Let's say we had a spacecraft with humans on the warmest part of Mars from which i read on wiki gets up to about 70 degrees f. <font color="#ff0000"><strong> If you wanted to, could you just run outside while holding your breath and then run back inside to get your breath without experiencing any real damaging effects?</strong></font> My second question is, what would climate feel like on Mars on the human skin. If it was 68 degrees, would it feel like 68 degrees or would it feel hotter or warmer. For instance, in Minnesota, when it's 80 degrees with a very high humidity, it feels much hotter than what it actually is. So am i right in assuming a 70 degree temp on Mars would feel much colder than just a regular 70 degree day here on Earth? <br />Posted by brandbll</DIV><br /><br />Actually you would have to <strong>exhale </strong>your breath before going outside. If you tried to hold a lungful of air, and then went outside, the pressure change could damage your lungs.</p><p>I imagine you could remain conscious for about as long as you could hold your breath in an exhaled condition. Maybe 30 seconds if you are in good shape. The air would feel like a dry warm day on Mt Everest - if Mt Everest could ever warm up! [Air pressure on Mt Everest = 0.29 atmospheres, The air pressure at the bottom of Hellas on Mars (lowest point) is about 0.012 atmospheres, which is barely high enough that water could exist as a liquid.] As others have commented, the low air pressure could cause embolisms and the 'bends'. I think that repeated exposure to this low a pressure could lead to brain and organ damage from bubbles in the veins.</p> <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>