The organizational structure follows logically from one point to the next to support the author's central idea about the thermometers that can save lives. The first paragraph descries heatstroke and introduces a pill that can help prevent heatstroke. The second paragraph describes how the thermometer can help prevent heatstroke, The third paragraph begins with one of the drawbacks about the pill.
Spatial order is usually used to describe a landscape, park or something the speaker is seeing. Cause and effect describes an event then all of the things that happen because of the event. Compare and contrast explains the similarities and difference between at least two things.
