David Anderson asked:
If human body temperature is 37 degrees why do we feel hot when itís 37 degrees outside?
Kat - Thereís two reasons for this. 37 degrees is our internal core temperature and the temperature thatís on our skin is probably a bit lower. I donít know if this is specific to ladies but often your feet are a bit colder than the rest of your body and my boyfriend always whinges about it. 37 degrees is your core body temperature. Temperatures that are lower than that will still feel hot to us on the outside. The other reason is that it gets harder and harder to cool down your body the hotter it gets, the nearer it gets to 37 degrees. Basically weíve evolved systems in our bodies that kick in to cool us down before we get as hot as 37 degrees. Itís really to protect us because once you start to approach a temperature of 37 degrees it does get very difficult to keep yourself cool. Sweat doesnít evaporate very easily, so you canít cool yourself down.
Chris - Some people say that the dinosaurs struggled with this because they had something called gigantothermy. Going back to Les in Overís swede once you have a very big body you donít have a big surface area relative to the volume inside you and your metabolic rate is producing all of these chemical reactions that are very exothermic. They give out a lot of energy. Getting rid of that excess heat can be really quite tricky. Some of these dinosaurs struggled to keep themselves cool enough. Although they were effectively cold-blooded because they were reptiles they were effectively warm-blooded. Right in the core of the dinosaur they were so hot from not being able to get all their heat out that they were effectively as warm blooded as you and I.
Kat: Getting too hot is really very damaging for your bodyís reactions once you get over a certain temperature you just canít function properly.