Question

On suffering from fever which will lower down your body temperature, more ice or ice cold water and why?

Answer 1

Latent Heat:

The heat required to change the state of a substance without changing temperature is known as latent heat.

Latent heat of fusion:

1. Latent heat of fusion for a solid is defined as the quantity of heat required in Joules to convert 1 Kg of solid to liquid without changing temperature.
2. For example: Latent heat of fusion of ice is $3.34\times {10}^5\mathrm{J}/\mathrm{kg}$.

Conclusion:

1. Ice will lower body temperature more as compared to ice-cold water and this is because the latent heat of fusion for ice (i.e., $3.34\times {10}^5\mathrm{J}/\mathrm{kg}$) is more as compared to ice-cold water.
2. The latent heat of ice of fusion is more than ice-cold water because it first changes its state and then converts into ice-cold water.

Thus, ice is expected to absorb more heat from the body and hence, provide a more cooling effect.