3.1. Thermal burns
3.1.1. Flash and flame burns
Flame is the most common cause of burns in adults and elderly individuals are the main population affected by this type of burn in England and Wales. Flames produce deep burns especially if clothes have been on fire, and are usually associated with inhalational injury and trauma. On the other hand, flash burns produce injuries that differ depending on the type and amount of fuel that explodes (Hijar-Medina et al., 1992; Forjuoh, 1998; Lentz, 2009; Sanford and Gamelli, 2014).
3.1.2. Scalds
Scalds are the main cause of burns in children and frequently in elderly people. In Europe, 25% of patients hospitalised for thermal injuries are children aged 0–4 years; of these, 90% suffer from scalds and in 90%, the total body surface area (TBSA) affected was <20%. Scalds are usually caused by spilling hot water or by using too hot water for bathing. Toddlers that accidentally fall into a bath of hot water will struggle and move about, thus producing multiple splash burns and making the border of the injury ill-defined. This type of burn depends not only on the water temperature but also on the skin thickness and duration of exposure (Hijar-Medina et al., 1992; Forjuoh, 1998; Lentz, 2009).
Scalds can also be caused by grease and hot oils, which produce deeper burns. Usually, patients who have grease burns on their lower extremities require surgery (Schubert et al., 1990; Bill et al., 1996; Klein et al., 2005).
3.1.3. Contact burns
Contact burns are common in industry; loss of consciousness (for different reasons) is the main cause. Hot metal, plastic, glass and coal are the main elements that produce this type of burn. Their severity hinges on the time of exposure (Steinstraesser and Al-Benna, 2013; Sanford and Gamelli, 2014).
3.1.4. Tar burns
Tar is a viscous, waxy substance derived from petroleum that has a high boiling point (140–232°C) and various industrial applications, such as surfacing roads and roofing (Stratta et al., 1983; Steinstraesser and Al-Benna, 2013).
Tar is associated with deep burns for three reasons: (1) when splashed, it cools rapidly to between 93°C and 104°C in the air; (2) when it contacts the skin, it cools and solidifies; and (3) it adheres to the skin, producing a continuous injury (Demling et al., 1980; Bose and Tredget, 1982; Stratta et al., 1983).
If the tar is still hot when the patient arrives to the medical facility, it should be rapidly cooled with room temperature water to prevent deeper burns; however, removal is not essential despite allowing an early assessment of the injury. Mechanical or manual debridement is painful and will also remove viable underlying skin; therefore, the tar should only be removed by qualified personnel (Demling et al., 1980; Bose and Tredget, 1982; Stratta et al., 1983; Robinett et al., 2010; Steinstraesser and Al-Benna, 2013).