I have been in the south woods heavily since the 70s. Chaps are much better than nothing but Boots protect your foot which pigmy rattlers can fasten to. So if you are wanting complete protection, wear boots. If you cannot find a pair of boots to fit good, again, chaps are better than nothing but they are hot if your hunting.
Otherwise just watch where your walking very closely.
Many Bites are from someone who grabbed a snake that they thought was dead or other preventatable activity.