"Hot in / So hot in here." These are the wise words once sung by the great rap artist Nelly. But also, our exact sentiments every time we descend the subway stairs. Or, walk out of our apartments. Or, even attempt strolling by the Hudson. Yes, these days can be blistering at worst and tolerable at best. That is, if you're not equipped with some stay-cool tips to help ventilate appropriately. Here's our how-to video for that very thing.