Hot Box Safety Features 21/3/12 ND Brown Ltd – Hot Box Safety Features March 2012 . N D Browns have issued a new document detailing all the safety features on our fleet of Asphalt Hot Box rental vehicles. Incl; Chapter 8 and beacons. Access and egress with 3 points of contact. Operative safety features. Additional safety features offered by N D Brown only. Please contact us if you would like a copy 01902 791991.