Introduction

Accidental hypothermia is one of major challenges faced by today's medicine.

Medical professionals dealing with hypothermic patients experience practical difficulties in every phase of treatment of the disorder. Shortage of efficient means of measurement in prehospital phase results in difficulties in diagnosis. Dilemmas concerning qualification to particular rewarming methods follow. Reliable medical data upon which efficacy of medical actions can be estimated is scarce, whilst accepted protocols are based usually on clinical observations or opinions of experts. Many of these issues are caused directly or indirectly by shortage of reliable epidemiological indicators. Without knowing the actual size of the problem we are unable to assign adequate importance to hypothermia nor determine the priorities of planned actions.

Incidence, mortality and fatality rates

To assess epidemiological situation, negative population health measures are used, these include: incidence rate, mortality rate and fatality rate.

Incidence rate, or the risk of occurrence of a disease in a population, states the number of people who are affected by the disease (number of new incidences of the disease) in a given period of observation (e.g. a year) divided by population at risk (100,000 or 10,000 people in a population is often utilised) [1]. Incidence rate is an important measure of health situation of a population. Monitoring of incidence rate enables assessment of changes in different time periods and makes early response to needs possible. It is also a helpful indicator taken into consideration when planning means of treatment and prevention of disease occurrences.

Number of deaths and population on a given area allow to calculate death-related indicators. Mortality and fatality rates should not be mistaken. Mortality rate is a number of deaths caused by a given disease in a given time period (e.g. a year) divided by population at risk (per 100,000 or 10,000 people in a population) in the studied time period. On the other hand, fatality rate is a ratio of deaths caused by a given disease and sum of all suffering from it (treated and deceased) in an analysed period of observation [1].