Dear Swami, When I was working a show the other night, we were required to wear a hard hat at all times. At some shows I've worked, hard hats are required only if it is outdoors. At one inside event I was told not to wear one and that only riggers should wear them. What's the really story? When should I wear a hard hat and when should I not wear one? Signed, Hard Hatted Dear HH, The best protection for the inside of the head is knowledge but the best protection for the outside of the head is a hard hat or a helmet. If work being done overhead, then there is a possibility that something could be dropped and head protection should be worn whether indoors or out. When riggers or anyone else are

Dear Swami Candela, What are the differences and similarities between voltage drop and I-squared-R loss? I know that they are calculating something different, but they seem linked in more ways than they are not. Signed, At a Loss Dear Loss, The universe connects many dots unbeknownst to us. In this case, voltage drop and losses due to I-squared-R are related by Ohm's law (V = I x R). If start with the power formula (P = V x I) and replace V using Ohm's law, you get P = (I x R) x I, which is the same as I x I x R, or I squared times R. That's the formula for the I-squared-R losses in a system. If you multiply it by the time, then it measures the energy lost to heat. Voltage drop is straight u