When should "度" be used? When should "量" be used? I noticed both 度 and 量 mean "amount, number". It looks like they are not exchangeable. Am I right? 

For example, I saw 温度，湿度，长度，宽度，高度，角度， but never saw 温量，湿量，长量，宽量，高量，角量。I also feel 重量，容量，含量，数量 are fixed combinations too. Is there a rule about where to use which?
度 is measurement for length, height or level  (difference between levels is measured in distance )

量 is measurement for volume (something to do with space available or occupied)

As nouns, they are not interchangeable

量度 (v ) to measure ( length or volume)

量 (v) to measure ( length or volume)

度 (v) to measure ( length)