4-8-8-7: GLARE AND HEAT:
   A.   Compliance Required: Any use established in the M-1 Restricted Manufacturing District after the effective date hereof shall be so operated as to comply with the performance standards governing glare and heat as set forth hereinafter. No use lawfully established on the effective date hereof shall be so altered or modified as to conflict with, or further conflict with, the performance standards governing glare and heat established hereinafter.
   B.   Regulations: In the M-1 Restricted Manufacturing District, any operation producing intense glare or heat shall be performed within a completely enclosed building in such a manner as not to create a public nuisance or hazard along lot lines. Exposed sources of light shall be shielded so as not to create a public nuisance or hazard or create a nuisance along lot lines.