Or even better, you can use one of the heaters in the save I showed you (the aray one), replacing the hot aray with a cold one using the prop tool.
See if this save helps you - id:1708903 . Also, for the freezing cryo laser, you could use wall type life (the blue one) in a 2px by anynumberpx setup instead of gol type 2px by 2px.
See if you can attach the pscn and nscn to the pcln without using walls. (hint: use insl to seperate the pcln and pscn/nscn so they do not melt)