Yes, I understand that having crossed arms may simply indicate that you are cold, or that it's a
comfortable position for you to hold your arms. However, your audience will unconsciously take your folded arms to mean that you are closing yourself off from the conversations. Having your arms crossed in front of your body effectively creates a barrier signifying to others that you are distancing yourself from the conversation.
If you want to appear open and interested then this is a gesture you should avoid. Interestingly, studies have shown that audience members sitting with crossed arms were far less likely to think favourably of a presenter (or what they present) than those with a more open posture.
If you want to 'be' open you must ensure that your body language is open. Apparently we not only signal our openness to our audience, but to our brains as well!