Metalloids are elements that have both metal and nonmetal properties
Chemical property is when it's observed during a reaction in which the chemical composition or identity of the substance is changed. physical properties is when properties that do change the chemical nature of matter.
example for this is smell, color, freezing point, etc.
Yes this is true as in cold conditions our body doesn't feel the urge of water therefore we may become dehydrated not even knowing about it and of course in hot coditions we sweat therefore we loose water.
Hope this helps :).