plants cooling

This is not a professional matter. In a professional context my problem would be the usual, heating up a green house in a cool climate. Im just curios if anybody heard of cooling mats (or pads) in stead of heating mats? Cause in my apartment I can control humidity, ad som extra lighting and so on. If I would be living in a house I would simply turn the heat of in spare room. But we don´t have a spare room. And since swedish houses are extremly good isolated and heated through central piping system trough out the town.