I'm 40 years old, have good eye sight, good overall health, and only tow at night when I have to. Even with perfect vision, you just can't see as well at night as during the days. Critters are more likely to be on the road, if you have a blow out you won't see it in the mirrors, etc.
My vehicles are new, and run fine in the heat of the day. One concession I will make while driving during the day is I will slow down. I have LT tires on my trailer, and usually tow around 70 MPH. If it is above 100* I slow down to 65. Above 110*, I will slow down further. Still better than driving at night.