I have a Chile Rose and a Mexican Red Knee and I don't use a heatmat with either of them. If they are kept in a room that is centrally heated and you feel comfy in that room then the spider will too. I do think though that glass tanks for them are colder for them than plastic tanks. Sorry I can't help any more as I have no experience of heatmats.

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Proud owner of
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5 cockatiels
12 budgies
33 tarantulas
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